Large IP Pool
Hello,
We are in a project of deploying 10.000 clients into the field. We want to assign a B class IP Pool(178.17.X.X) for this group of users. But as far as I know, CS ACS Win can support an IP Pool of whole C Class at most. Is there a configuration option or a workaround to solve this issue?
Best tegards
Yes, ACS only allows a C-class subnet to be added in as a pool of addresses. If you want to add an entire B-class you'd have to add multiple pools, something like the following:
ippool0 from 178.18.0.1-178.18.0.254
ippool1 from 178.18.1.1-178.18.1.254
ippool2 from 178.18.2.1-178.18.2.254
ippool254 from 178.18.254.1-178.18.254.254
ippool255 from 178.18.255.1-178.18.255.254
Then under the ACS group you would move all these pools into the Selected Pools column, so ACS will assign the IP address out of a first available pool.
Similar Messages
-
I am running a DW application on 11.2.0.1, linux, using AMM. We have 64G memory, of which 45G is (theoretically) allocated to ORACLE.
I have noticed that the PGA size has increased substantially ( I'd expect this, being a DW with an MDX miiddle ), to about 40G, but I also notice that the SGA has remained static at about 20G (it was 25G). I've ailso noticed that the shared pool has ballooned from a few hundred MB to 7Gb in a matter of months. This is definitely increasing I/O which is unwanted.
Why does the shared pool get so big ? We are not a high turnover/large user number operation and parse times are a very small proportion of overall query time. Will a flush shrink the shared pool memory allocation or will it jsut clear the space ?OK, the allocated PGA will of course increase in response to demand, but I do not believe that the total PGA + SGA will ever break your 45G limit, and never has. I guess OEM is mis-representing something.
wrt the performance issue, I would question whether the size of the shared pool is in fact impacting on performance. The way I look at it is that no end user ever telphoned the help desk to say "the shared pool is too big" or "disc I/O is excessive". They may telephone to say "my queries are too slow". This throws you into the realm of query tuning, which would be a different topic.
wrt to memory usage and AMM, I believe that AMM does tend to assign more memory than needed to the shared_pool. If this really is a problem in your instance (and we don't know this yet) then you can set minimum values for the other SGA structures (usually, db_cache_size) to prevent this.
Hope this helps.
J. -
I have a NSS Pool spanning 4 SAN volumes of 2TB a piece for a total pool of 8tb. No problems, until I need more space--but that's another issue. I wanted see if anyone has recommendations for NSS settings for such a big pool. I am using the defaults. Why I ask is that we are implementing a new Backup solution (Commvault) and our servers that have smaller pools, not spanning partitions get much better throughput.---identical hardware, HBA, RAM, etc.---just not 8tb of SAN volume. More of a ONE to ONE ratio---POOL to VOLUME to SAN VOLUME to Partition.
Could it be that the POOL spanning and it's size causing slowness?Yes, the size and spanning would make this a little slower. If it were me, I would never do it like this. Just think if something happened to that pool and you had to rebuild it. A rule of thumb for a rebuild it 45 min to an hour for every 100G of uged disk space. As that pools starts to fill up, it will take days to repair it. I would not want the down to to do that. Even if you didn't repair it with rebuild, you decided that you were going to delete it an recreate it and then restore the data. That too will take a long time. To get back to the question, yes, it would slow it down.
jgray -
Increased Shared Pool size longer hot backup time?
Hello,
I have hot backup that usually took 2 hours to complete. Then we had to increase Shared pool size from 280Mb to 380Mb due to some performance issue.
One week after increase of size the hot backup is taking 4 hours to complete. Since there was no other changes to the system I am suspecting size increase
of Shared Pool from 280Mb to 380Mb might be is reason for such drastic increase of backup time.
I would like to get your comments on my suspicion to the problem.
thank youPaul.S wrote:
One week after increase of size the hot backup is taking 4 hours to complete. Since there was no other changes to the system I am suspecting size increase of Shared Pool from 280Mb to 380Mb might be is reason for such drastic increase of backup time.Hmm... at first glance it does not seem that this is the problem.. but perhaps it contributes to it.
When a SQL hits the SQL engine, the 1st thing the SQL engine does is determine if there is an existing parsed and ready-to-use copy of that SQL. If there is, that existing SQL is re-used - thus the name SQL Shared Pool. The resulting soft parse of the SQL is a lot faster (or should be) than a hard parse . A hard parse is where there is no re-usable copy, and the SQL needs to be parsed, validated and execution plan determined, etc.
Kind of like re-using an existing compiled program (with different input data) versus compiling that program before using it. (and that is what source SQL is - a program that needs to be compiled).
Okay, now what happens if there 100's of 1000's of SQLs in your shared pool? The scan that the SQL engine does to determine if there is a re-usable cursor, becomes pretty slow. A soft parse quickly becomes very expensive.
The problem is typically clients that create SQLs that are not sharable (where the input data is hardcoded into the program, instead of input variables to the program). In other words, SQLs that do not use bind variables.
Each and every hardcoded SQL that hits the SQL engine, is now a brand new SQL. And requires storage in the SQL Shared Pool. Shared Pool footprint grows and you start getting errors like insufficient shared pool memory.. and increase the shared pool which means even more space to store even more unique non-sharable SQLs and making soft and hard parses even more expensive.
Like moving the wall a few metres further and then running even faster into it. !http://www.pprune.org/forums/images/smilies2/eusa_wall.gif!
Now if the backup fires off a load of SQLs against the SQL engine, the fast soft/hard parses can now be a lot slower than previously, thanks to a larger shared pool that now caters for more junk than before.
Unsure if this is the problem that you are experiencing.. but assuming that your suspicion is correct, it offers an explanation as to why there can be a degradation in performance. -
Migrating Protection group to new storage pool
Hello all running DPM 2012. The environment was setup prior to my arrival and it was setup with 10 1.5TB storage pools. I heard the thinking was this was the recommended size for storage pools. Problem is now we are/have run out of disk space
on those storage pools and jobs are failing with "DPM does not have sufficient storage space available on the recovery point volume to create new recovery points (ID 214)"
I have created new 4 new storage pools of 10TB each and I want to know how I can migrate the protection group data to the new storage pools and have the protection group use the new storage pool moving forward. I want to empty the smaller storage pools
so I can kill them off and create larger storage pools.
Unfortunately the GUI does not allow me to point to specific storage pools, it should, and I'm not familiar with DPM Shell commands.
Any suggestions would be appreciated.Hi,
http://technet.microsoft.com/en-us/library/dd282970.aspx
The following commands can be used with the ntdisk number as seen in either the get-DPMDISK output, the Windows Disk Management GUI or DPM Management - Disks GUI. In my example disk-0 is the system/boot disk and not used by DPM storage pool.
EXAMPLE These commands show the migrations going from NTDisk 1,2,3,4,5,6,7,8,9,10 to NTDisks 11,12,13,14
$source = get-dpmdisk -dpmserver DPM-SVR-NAME | where {1,2,3,4,5,6,7,8,9,10 -contains $_.ntdiskid}
$source
$destination = get-dpmdisk -dpmserver DPM-SVR-NAME | where {11,12,13,14 -contains $_.ntdiskid}
$destination
Once you are satisfied the outputs are what you want, then run the following to do the migration:
MigrateDatasourceDataFromDPM.ps1 -DPMServername DPM-SVR-NAME -source $source -destination $destination
Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Regards, Mike J. [MSFT]
This posting is provided "AS IS" with no warranties, and confers no rights. -
Can large page improve timesten performance on aix??
hello, chris:
Can large page imporove timesten performance on aix? we havenot test it yet, I just want to know whether it is ok?? thank you.Enabling large page support on AIX may help performance under some circumstances (typically with large datastores). TimesTen does support use of large pages on AIX and no special action is needed on the TimesTen side to utilise large pages. Here is some information on this which should eventually appear in the TimesTen documentation.
The TimesTen shared memory segment for AIX has been created with the flags
( SHM_PIN | SHM_LGPAGE) necessary for large page support for many releases.
It used to be the case that special kernel flags needed to be enabled so it
was never documented as being supported. Subsequent AIX releases have made
enabling large pages a matter of system administration.
1) Enable capabilities (chuser)
2) Configure page pool (vmo -r)
3) Enable memory pining (vmo -p)
4) [restart timesten daemons]
The documentation is quoted below.
AIX maintains separate 4 KB and 16 MB physical memory pools. You can
specify the amount of physical memory in the 16 MB memory pool using the vmo
command. Starting with AIX 5.3, the large page pool is dynamic, so the amount
of physical memory that you specify takes effect immediately and does not
require a system reboot. The remaining physical memory backs the 4 KB virtual
pages.
AIX treats large pages as pinned memory. AIX does not provide paging
support for large pages. The data of an application that is backed by large
pages remains in physical memory until the application completes. A security
access control mechanism prevents unauthorized applications from using large
pages or large page physical memory. The security access control mechanism
also prevents unauthorized users from using large pages for their
applications. For non-root user ids, you must enable the CAP_BYPASS_RAC_VMM
capability with the chuser command in order to use large pages. The following
example demonstrates how to grant the CAP_BYPASS_RAC_VMM capability as the
superuser:
# chuser capabilities=CAP_BYPASS_RAC_VMM,CAP_PROPAGATE <user id>
The system default is to not have any memory allocated to the large page
physical memory pool. You can use the vmo command to configure the size of
the large page physical memory pool. The following example allocates 4 GB to
the large page physical memory pool:
# vmo -r -o lgpg_regions=64 -o lgpg_size=16777216
To use large pages for shared memory, you must enable the SHM_PIN shmget()
system call with the following command, which persists across system reboots:
# vmo -p -o v_pinshm=1
To see how many large pages are in use on your system, use the vmstat -l
command as in the following example:
# vmstat -l
kthr memory page faults cpu large-page
r b avm fre re pi po fr sr cy in sy cs us sy id wa alp flp
2 1 52238 124523 0 0 0 0 0 0 142 41 73 0 3 97 0 16 16
From the above example, you can see that there are 16 active large pages, alp, and
16 free large pages, flp.
Documentation is at:
http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibmaix.prftungd/doc/prftungd/large_page_ovw.htm
Chris -
Are there any interfaces to query within SJSWS 6.1 that will provide run-time statistics for JDBC pools? I'm looking for number currently in use, max pool size (how large the pool has grown, not the static max), etc.
thanks,
-chrisHi Simon,
"Simon Spruzen" <[email protected]> wrote in message
news:[email protected]..
WebLogic 6.1 SP2 (NT)
There are 15 execute threads configured.
There is one JDBC connection pool configured. In the monitoring screen(my-domain>
JDBC Connection ...> my-pool> Active JDBC Conn...) I get these stats:
Connections High......13Maximum number of connections reseved
from the pool the same time.
Connections Total.....26Running count of borrowed connections
Connections...........8Current number of borrowed connections.
1. Why is Connections High less than Connections Total?CH is a maximum, CT is a running count.
2. Why would Connections Total be slowly creeping up? Does this imply thata connection
isn't being returned to the pool?Brcause it's natural for a counter to grow.
4. What's the relationship between Connections, Connections Total andConnections
High?They're mainly run-time characteristics of a connection pool.
Regards,
Slava Imeshev -
LVM Volumes not available after update
Hi All!
I haven't updated my system for about two months and today I updated it. Now I have the problem that I cannot boot properly. I have my root partition in an LVM volume and on boot I get the message
ERROR: device 'UUID=xxx' not found. Skipping fs
ERROR: Unable to find root device 'UUID=xxx'
After that I land in the recovery shell. After some research I found, that "lvm lvdisplay" showed that my volumes where not available and I had to reenable them with "lvm vgchange -a y".
Issuing any lvm command also produced the following warning:
WARNING: lvmetad is running but disabled. Restart lvmetad before enabling it!
Anyway, after issuing the commands and exiting the recovery shell, the system booted again. However, I would prefer being able to boot without manual actions.
Thanks in advance!
Further information:
vgdisplay
--- Volume group ---
VG Name ArchLVM
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 1
Max PV 0
Cur PV 1
Act PV 1
VG Size 232.69 GiB
PE Size 4.00 MiB
Total PE 59568
Alloc PE / Size 59568 / 232.69 GiB
Free PE / Size 0 / 0
VG UUID SoB3M1-v1fD-1abI-PNJ3-6IOn-FfdI-0RoLK5
lvdisplay (LV Status was 'not available' right after booting)
--- Logical volume ---
LV Path /dev/ArchLVM/Swap
LV Name Swap
VG Name ArchLVM
LV UUID XRYBrz-LojR-k6SD-XIxV-wHnY-f3VG-giKL6V
LV Write Access read/write
LV Creation host, time archiso, 2014-05-16 14:43:06 +0200
LV Status available
# open 0
LV Size 8.00 GiB
Current LE 2048
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 254:0
--- Logical volume ---
LV Path /dev/ArchLVM/Root
LV Name Root
VG Name ArchLVM
LV UUID lpjDl4-Jqzu-ZWkq-Uphc-IaOo-6Rzd-cIh5yv
LV Write Access read/write
LV Creation host, time archiso, 2014-05-16 14:43:27 +0200
LV Status available
# open 1
LV Size 224.69 GiB
Current LE 57520
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 254:1
/etc/fstab
# /etc/fstab: static file system information
# <file system> <dir> <type> <options> <dump> <pass>
# /dev/mapper/ArchLVM-Root
UUID=2db82d1a-47a4-4e30-a819-143e8fb75199 / ext4 rw,relatime,data=ordered 0 1
#/dev/mapper/ArchLVM-Root / ext4 rw,relatime,data=ordered 0 1
# /dev/sda1
UUID=72691888-a781-4cdd-a98e-2613d87925d0 /boot ext2 rw,relatime 0 2
/etc/mkinitcpio.conf
# vim:set ft=sh
# MODULES
# The following modules are loaded before any boot hooks are
# run. Advanced users may wish to specify all system modules
# in this array. For instance:
# MODULES="piix ide_disk reiserfs"
MODULES=""
# BINARIES
# This setting includes any additional binaries a given user may
# wish into the CPIO image. This is run last, so it may be used to
# override the actual binaries included by a given hook
# BINARIES are dependency parsed, so you may safely ignore libraries
BINARIES=""
# FILES
# This setting is similar to BINARIES above, however, files are added
# as-is and are not parsed in any way. This is useful for config files.
FILES=""
# HOOKS
# This is the most important setting in this file. The HOOKS control the
# modules and scripts added to the image, and what happens at boot time.
# Order is important, and it is recommended that you do not change the
# order in which HOOKS are added. Run 'mkinitcpio -H <hook name>' for
# help on a given hook.
# 'base' is _required_ unless you know precisely what you are doing.
# 'udev' is _required_ in order to automatically load modules
# 'filesystems' is _required_ unless you specify your fs modules in MODULES
# Examples:
## This setup specifies all modules in the MODULES setting above.
## No raid, lvm2, or encrypted root is needed.
# HOOKS="base"
## This setup will autodetect all modules for your system and should
## work as a sane default
# HOOKS="base udev autodetect block filesystems"
## This setup will generate a 'full' image which supports most systems.
## No autodetection is done.
# HOOKS="base udev block filesystems"
## This setup assembles a pata mdadm array with an encrypted root FS.
## Note: See 'mkinitcpio -H mdadm' for more information on raid devices.
# HOOKS="base udev block mdadm encrypt filesystems"
## This setup loads an lvm2 volume group on a usb device.
# HOOKS="base udev block lvm2 filesystems"
## NOTE: If you have /usr on a separate partition, you MUST include the
# usr, fsck and shutdown hooks.
HOOKS="base udev autodetect modconf block lvm2 filesystems keyboard fsck"
# COMPRESSION
# Use this to compress the initramfs image. By default, gzip compression
# is used. Use 'cat' to create an uncompressed image.
#COMPRESSION="gzip"
#COMPRESSION="bzip2"
#COMPRESSION="lzma"
#COMPRESSION="xz"
#COMPRESSION="lzop"
#COMPRESSION="lz4"
# COMPRESSION_OPTIONS
# Additional options for the compressor
#COMPRESSION_OPTIONS=""
/boot/grub/grub.cfg
# DO NOT EDIT THIS FILE
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
### BEGIN /etc/grub.d/00_header ###
insmod part_gpt
insmod part_msdos
if [ -s $prefix/grubenv ]; then
load_env
fi
if [ "${next_entry}" ] ; then
set default="${next_entry}"
set next_entry=
save_env next_entry
set boot_once=true
else
set default="0"
fi
if [ x"${feature_menuentry_id}" = xy ]; then
menuentry_id_option="--id"
else
menuentry_id_option=""
fi
export menuentry_id_option
if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi
function savedefault {
if [ -z "${boot_once}" ]; then
saved_entry="${chosen}"
save_env saved_entry
fi
function load_video {
if [ x$feature_all_video_module = xy ]; then
insmod all_video
else
insmod efi_gop
insmod efi_uga
insmod ieee1275_fb
insmod vbe
insmod vga
insmod video_bochs
insmod video_cirrus
fi
if [ x$feature_default_font_path = xy ] ; then
font=unicode
else
insmod part_msdos
insmod lvm
insmod ext2
set root='lvmid/SoB3M1-v1fD-1abI-PNJ3-6IOn-FfdI-0RoLK5/lpjDl4-Jqzu-ZWkq-Uphc-IaOo-6Rzd-cIh5yv'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint='lvmid/SoB3M1-v1fD-1abI-PNJ3-6IOn-FfdI-0RoLK5/lpjDl4-Jqzu-ZWkq-Uphc-IaOo-6Rzd-cIh5yv' 2db82d1a-47a4-4e30-a819-143e8fb75199
else
search --no-floppy --fs-uuid --set=root 2db82d1a-47a4-4e30-a819-143e8fb75199
fi
font="/usr/share/grub/unicode.pf2"
fi
if loadfont $font ; then
set gfxmode=auto
load_video
insmod gfxterm
fi
terminal_input console
terminal_output gfxterm
if [ x$feature_timeout_style = xy ] ; then
set timeout_style=menu
set timeout=5
# Fallback normal timeout code in case the timeout_style feature is
# unavailable.
else
set timeout=5
fi
### END /etc/grub.d/00_header ###
### BEGIN /etc/grub.d/10_linux ###
menuentry 'Arch Linux' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-2db82d1a-47a4-4e30-a819-143e8fb75199' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_msdos
insmod ext2
set root='hd0,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 72691888-a781-4cdd-a98e-2613d87925d0
else
search --no-floppy --fs-uuid --set=root 72691888-a781-4cdd-a98e-2613d87925d0
fi
echo 'Loading Linux linux ...'
linux /vmlinuz-linux root=UUID=2db82d1a-47a4-4e30-a819-143e8fb75199 rw quiet
echo 'Loading initial ramdisk ...'
initrd /initramfs-linux.img
submenu 'Advanced options for Arch Linux' $menuentry_id_option 'gnulinux-advanced-2db82d1a-47a4-4e30-a819-143e8fb75199' {
menuentry 'Arch Linux, with Linux linux' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-advanced-2db82d1a-47a4-4e30-a819-143e8fb75199' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_msdos
insmod ext2
set root='hd0,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 72691888-a781-4cdd-a98e-2613d87925d0
else
search --no-floppy --fs-uuid --set=root 72691888-a781-4cdd-a98e-2613d87925d0
fi
echo 'Loading Linux linux ...'
linux /vmlinuz-linux root=UUID=2db82d1a-47a4-4e30-a819-143e8fb75199 rw quiet
echo 'Loading initial ramdisk ...'
initrd /initramfs-linux.img
menuentry 'Arch Linux, with Linux linux (fallback initramfs)' --class arch --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-linux-fallback-2db82d1a-47a4-4e30-a819-143e8fb75199' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_msdos
insmod ext2
set root='hd0,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1 72691888-a781-4cdd-a98e-2613d87925d0
else
search --no-floppy --fs-uuid --set=root 72691888-a781-4cdd-a98e-2613d87925d0
fi
echo 'Loading Linux linux ...'
linux /vmlinuz-linux root=UUID=2db82d1a-47a4-4e30-a819-143e8fb75199 rw quiet
echo 'Loading initial ramdisk ...'
initrd /initramfs-linux-fallback.img
### END /etc/grub.d/10_linux ###
### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###
### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###
### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###
### BEGIN /etc/grub.d/41_custom ###
if [ -f ${config_directory}/custom.cfg ]; then
source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f $prefix/custom.cfg ]; then
source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###
### BEGIN /etc/grub.d/60_memtest86+ ###
### END /etc/grub.d/60_memtest86+ ###
Last edited by Kirodema (2014-07-16 07:31:34)use_lvmetad = 0
lvm2-lvmetad is not enabled or running on my system. Shall I activate it?
# This is an example configuration file for the LVM2 system.
# It contains the default settings that would be used if there was no
# /etc/lvm/lvm.conf file.
# Refer to 'man lvm.conf' for further information including the file layout.
# To put this file in a different directory and override /etc/lvm set
# the environment variable LVM_SYSTEM_DIR before running the tools.
# N.B. Take care that each setting only appears once if uncommenting
# example settings in this file.
# This section allows you to set the way the configuration settings are handled.
config {
# If enabled, any LVM2 configuration mismatch is reported.
# This implies checking that the configuration key is understood
# by LVM2 and that the value of the key is of a proper type.
# If disabled, any configuration mismatch is ignored and default
# value is used instead without any warning (a message about the
# configuration key not being found is issued in verbose mode only).
checks = 1
# If enabled, any configuration mismatch aborts the LVM2 process.
abort_on_errors = 0
# Directory where LVM looks for configuration profiles.
profile_dir = "/etc/lvm/profile"
# This section allows you to configure which block devices should
# be used by the LVM system.
devices {
# Where do you want your volume groups to appear ?
dir = "/dev"
# An array of directories that contain the device nodes you wish
# to use with LVM2.
scan = [ "/dev" ]
# If set, the cache of block device nodes with all associated symlinks
# will be constructed out of the existing udev database content.
# This avoids using and opening any inapplicable non-block devices or
# subdirectories found in the device directory. This setting is applied
# to udev-managed device directory only, other directories will be scanned
# fully. LVM2 needs to be compiled with udev support for this setting to
# take effect. N.B. Any device node or symlink not managed by udev in
# udev directory will be ignored with this setting on.
obtain_device_list_from_udev = 1
# If several entries in the scanned directories correspond to the
# same block device and the tools need to display a name for device,
# all the pathnames are matched against each item in the following
# list of regular expressions in turn and the first match is used.
preferred_names = [ ]
# Try to avoid using undescriptive /dev/dm-N names, if present.
# preferred_names = [ "^/dev/mpath/", "^/dev/mapper/mpath", "^/dev/[hs]d" ]
# A filter that tells LVM2 to only use a restricted set of devices.
# The filter consists of an array of regular expressions. These
# expressions can be delimited by a character of your choice, and
# prefixed with either an 'a' (for accept) or 'r' (for reject).
# The first expression found to match a device name determines if
# the device will be accepted or rejected (ignored). Devices that
# don't match any patterns are accepted.
# Be careful if there there are symbolic links or multiple filesystem
# entries for the same device as each name is checked separately against
# the list of patterns. The effect is that if the first pattern in the
# list to match a name is an 'a' pattern for any of the names, the device
# is accepted; otherwise if the first pattern in the list to match a name
# is an 'r' pattern for any of the names it is rejected; otherwise it is
# accepted.
# Don't have more than one filter line active at once: only one gets used.
# Run vgscan after you change this parameter to ensure that
# the cache file gets regenerated (see below).
# If it doesn't do what you expect, check the output of 'vgscan -vvvv'.
# If lvmetad is used, then see "A note about device filtering while
# lvmetad is used" comment that is attached to global/use_lvmetad setting.
# By default we accept every block device:
filter = [ "a/.*/" ]
# Exclude the cdrom drive
# filter = [ "r|/dev/cdrom|" ]
# When testing I like to work with just loopback devices:
# filter = [ "a/loop/", "r/.*/" ]
# Or maybe all loops and ide drives except hdc:
# filter =[ "a|loop|", "r|/dev/hdc|", "a|/dev/ide|", "r|.*|" ]
# Use anchors if you want to be really specific
# filter = [ "a|^/dev/hda8$|", "r/.*/" ]
# Since "filter" is often overridden from command line, it is not suitable
# for system-wide device filtering (udev rules, lvmetad). To hide devices
# from LVM-specific udev processing and/or from lvmetad, you need to set
# global_filter. The syntax is the same as for normal "filter"
# above. Devices that fail the global_filter are not even opened by LVM.
# global_filter = []
# The results of the filtering are cached on disk to avoid
# rescanning dud devices (which can take a very long time).
# By default this cache is stored in the /etc/lvm/cache directory
# in a file called '.cache'.
# It is safe to delete the contents: the tools regenerate it.
# (The old setting 'cache' is still respected if neither of
# these new ones is present.)
# N.B. If obtain_device_list_from_udev is set to 1 the list of
# devices is instead obtained from udev and any existing .cache
# file is removed.
cache_dir = "/etc/lvm/cache"
cache_file_prefix = ""
# You can turn off writing this cache file by setting this to 0.
write_cache_state = 1
# Advanced settings.
# List of pairs of additional acceptable block device types found
# in /proc/devices with maximum (non-zero) number of partitions.
# types = [ "fd", 16 ]
# If sysfs is mounted (2.6 kernels) restrict device scanning to
# the block devices it believes are valid.
# 1 enables; 0 disables.
sysfs_scan = 1
# By default, LVM2 will ignore devices used as component paths
# of device-mapper multipath devices.
# 1 enables; 0 disables.
multipath_component_detection = 1
# By default, LVM2 will ignore devices used as components of
# software RAID (md) devices by looking for md superblocks.
# 1 enables; 0 disables.
md_component_detection = 1
# By default, if a PV is placed directly upon an md device, LVM2
# will align its data blocks with the md device's stripe-width.
# 1 enables; 0 disables.
md_chunk_alignment = 1
# Default alignment of the start of a data area in MB. If set to 0,
# a value of 64KB will be used. Set to 1 for 1MiB, 2 for 2MiB, etc.
# default_data_alignment = 1
# By default, the start of a PV's data area will be a multiple of
# the 'minimum_io_size' or 'optimal_io_size' exposed in sysfs.
# - minimum_io_size - the smallest request the device can perform
# w/o incurring a read-modify-write penalty (e.g. MD's chunk size)
# - optimal_io_size - the device's preferred unit of receiving I/O
# (e.g. MD's stripe width)
# minimum_io_size is used if optimal_io_size is undefined (0).
# If md_chunk_alignment is enabled, that detects the optimal_io_size.
# This setting takes precedence over md_chunk_alignment.
# 1 enables; 0 disables.
data_alignment_detection = 1
# Alignment (in KB) of start of data area when creating a new PV.
# md_chunk_alignment and data_alignment_detection are disabled if set.
# Set to 0 for the default alignment (see: data_alignment_default)
# or page size, if larger.
data_alignment = 0
# By default, the start of the PV's aligned data area will be shifted by
# the 'alignment_offset' exposed in sysfs. This offset is often 0 but
# may be non-zero; e.g.: certain 4KB sector drives that compensate for
# windows partitioning will have an alignment_offset of 3584 bytes
# (sector 7 is the lowest aligned logical block, the 4KB sectors start
# at LBA -1, and consequently sector 63 is aligned on a 4KB boundary).
# But note that pvcreate --dataalignmentoffset will skip this detection.
# 1 enables; 0 disables.
data_alignment_offset_detection = 1
# If, while scanning the system for PVs, LVM2 encounters a device-mapper
# device that has its I/O suspended, it waits for it to become accessible.
# Set this to 1 to skip such devices. This should only be needed
# in recovery situations.
ignore_suspended_devices = 0
# ignore_lvm_mirrors: Introduced in version 2.02.104
# This setting determines whether logical volumes of "mirror" segment
# type are scanned for LVM labels. This affects the ability of
# mirrors to be used as physical volumes. If 'ignore_lvm_mirrors'
# is set to '1', it becomes impossible to create volume groups on top
# of mirror logical volumes - i.e. to stack volume groups on mirrors.
# Allowing mirror logical volumes to be scanned (setting the value to '0')
# can potentially cause LVM processes and I/O to the mirror to become
# blocked. This is due to the way that the "mirror" segment type handles
# failures. In order for the hang to manifest itself, an LVM command must
# be run just after a failure and before the automatic LVM repair process
# takes place OR there must be failures in multiple mirrors in the same
# volume group at the same time with write failures occurring moments
# before a scan of the mirror's labels.
# Note that these scanning limitations do not apply to the LVM RAID
# types, like "raid1". The RAID segment types handle failures in a
# different way and are not subject to possible process or I/O blocking.
# It is encouraged that users set 'ignore_lvm_mirrors' to 1 if they
# are using the "mirror" segment type. Users that require volume group
# stacking on mirrored logical volumes should consider using the "raid1"
# segment type. The "raid1" segment type is not available for
# active/active clustered volume groups.
# Set to 1 to disallow stacking and thereby avoid a possible deadlock.
ignore_lvm_mirrors = 1
# During each LVM operation errors received from each device are counted.
# If the counter of a particular device exceeds the limit set here, no
# further I/O is sent to that device for the remainder of the respective
# operation. Setting the parameter to 0 disables the counters altogether.
disable_after_error_count = 0
# Allow use of pvcreate --uuid without requiring --restorefile.
require_restorefile_with_uuid = 1
# Minimum size (in KB) of block devices which can be used as PVs.
# In a clustered environment all nodes must use the same value.
# Any value smaller than 512KB is ignored.
# Ignore devices smaller than 2MB such as floppy drives.
pv_min_size = 2048
# The original built-in setting was 512 up to and including version 2.02.84.
# pv_min_size = 512
# Issue discards to a logical volumes's underlying physical volume(s) when
# the logical volume is no longer using the physical volumes' space (e.g.
# lvremove, lvreduce, etc). Discards inform the storage that a region is
# no longer in use. Storage that supports discards advertise the protocol
# specific way discards should be issued by the kernel (TRIM, UNMAP, or
# WRITE SAME with UNMAP bit set). Not all storage will support or benefit
# from discards but SSDs and thinly provisioned LUNs generally do. If set
# to 1, discards will only be issued if both the storage and kernel provide
# support.
# 1 enables; 0 disables.
issue_discards = 0
# This section allows you to configure the way in which LVM selects
# free space for its Logical Volumes.
allocation {
# When searching for free space to extend an LV, the "cling"
# allocation policy will choose space on the same PVs as the last
# segment of the existing LV. If there is insufficient space and a
# list of tags is defined here, it will check whether any of them are
# attached to the PVs concerned and then seek to match those PV tags
# between existing extents and new extents.
# Use the special tag "@*" as a wildcard to match any PV tag.
# Example: LVs are mirrored between two sites within a single VG.
# PVs are tagged with either @site1 or @site2 to indicate where
# they are situated.
# cling_tag_list = [ "@site1", "@site2" ]
# cling_tag_list = [ "@*" ]
# Changes made in version 2.02.85 extended the reach of the 'cling'
# policies to detect more situations where data can be grouped
# onto the same disks. Set this to 0 to revert to the previous
# algorithm.
maximise_cling = 1
# Whether to use blkid library instead of native LVM2 code to detect
# any existing signatures while creating new Physical Volumes and
# Logical Volumes. LVM2 needs to be compiled with blkid wiping support
# for this setting to take effect.
# LVM2 native detection code is currently able to recognize these signatures:
# - MD device signature
# - swap signature
# - LUKS signature
# To see the list of signatures recognized by blkid, check the output
# of 'blkid -k' command. The blkid can recognize more signatures than
# LVM2 native detection code, but due to this higher number of signatures
# to be recognized, it can take more time to complete the signature scan.
use_blkid_wiping = 1
# Set to 1 to wipe any signatures found on newly-created Logical Volumes
# automatically in addition to zeroing of the first KB on the LV
# (controlled by the -Z/--zero y option).
# The command line option -W/--wipesignatures takes precedence over this
# setting.
# The default is to wipe signatures when zeroing.
wipe_signatures_when_zeroing_new_lvs = 1
# Set to 1 to guarantee that mirror logs will always be placed on
# different PVs from the mirror images. This was the default
# until version 2.02.85.
mirror_logs_require_separate_pvs = 0
# Set to 1 to guarantee that cache_pool metadata will always be
# placed on different PVs from the cache_pool data.
cache_pool_metadata_require_separate_pvs = 0
# Specify the minimal chunk size (in kiB) for cache pool volumes.
# Using a chunk_size that is too large can result in wasteful use of
# the cache, where small reads and writes can cause large sections of
# an LV to be mapped into the cache. However, choosing a chunk_size
# that is too small can result in more overhead trying to manage the
# numerous chunks that become mapped into the cache. The former is
# more of a problem than the latter in most cases, so we default to
# a value that is on the smaller end of the spectrum. Supported values
# range from 32(kiB) to 1048576 in multiples of 32.
# cache_pool_chunk_size = 64
# Set to 1 to guarantee that thin pool metadata will always
# be placed on different PVs from the pool data.
thin_pool_metadata_require_separate_pvs = 0
# Specify chunk size calculation policy for thin pool volumes.
# Possible options are:
# "generic" - if thin_pool_chunk_size is defined, use it.
# Otherwise, calculate the chunk size based on
# estimation and device hints exposed in sysfs:
# the minimum_io_size. The chunk size is always
# at least 64KiB.
# "performance" - if thin_pool_chunk_size is defined, use it.
# Otherwise, calculate the chunk size for
# performance based on device hints exposed in
# sysfs: the optimal_io_size. The chunk size is
# always at least 512KiB.
# thin_pool_chunk_size_policy = "generic"
# Specify the minimal chunk size (in KB) for thin pool volumes.
# Use of the larger chunk size may improve performance for plain
# thin volumes, however using them for snapshot volumes is less efficient,
# as it consumes more space and takes extra time for copying.
# When unset, lvm tries to estimate chunk size starting from 64KB
# Supported values are in range from 64 to 1048576.
# thin_pool_chunk_size = 64
# Specify discards behaviour of the thin pool volume.
# Select one of "ignore", "nopassdown", "passdown"
# thin_pool_discards = "passdown"
# Set to 0, to disable zeroing of thin pool data chunks before their
# first use.
# N.B. zeroing larger thin pool chunk size degrades performance.
# thin_pool_zero = 1
# This section that allows you to configure the nature of the
# information that LVM2 reports.
log {
# Controls the messages sent to stdout or stderr.
# There are three levels of verbosity, 3 being the most verbose.
verbose = 0
# Set to 1 to suppress all non-essential messages from stdout.
# This has the same effect as -qq.
# When this is set, the following commands still produce output:
# dumpconfig, lvdisplay, lvmdiskscan, lvs, pvck, pvdisplay,
# pvs, version, vgcfgrestore -l, vgdisplay, vgs.
# Non-essential messages are shifted from log level 4 to log level 5
# for syslog and lvm2_log_fn purposes.
# Any 'yes' or 'no' questions not overridden by other arguments
# are suppressed and default to 'no'.
silent = 0
# Should we send log messages through syslog?
# 1 is yes; 0 is no.
syslog = 1
# Should we log error and debug messages to a file?
# By default there is no log file.
#file = "/var/log/lvm2.log"
# Should we overwrite the log file each time the program is run?
# By default we append.
overwrite = 0
# What level of log messages should we send to the log file and/or syslog?
# There are 6 syslog-like log levels currently in use - 2 to 7 inclusive.
# 7 is the most verbose (LOG_DEBUG).
level = 0
# Format of output messages
# Whether or not (1 or 0) to indent messages according to their severity
indent = 1
# Whether or not (1 or 0) to display the command name on each line output
command_names = 0
# A prefix to use before the message text (but after the command name,
# if selected). Default is two spaces, so you can see/grep the severity
# of each message.
prefix = " "
# To make the messages look similar to the original LVM tools use:
# indent = 0
# command_names = 1
# prefix = " -- "
# Set this if you want log messages during activation.
# Don't use this in low memory situations (can deadlock).
# activation = 0
# Some debugging messages are assigned to a class and only appear
# in debug output if the class is listed here.
# Classes currently available:
# memory, devices, activation, allocation, lvmetad, metadata, cache,
# locking
# Use "all" to see everything.
debug_classes = [ "memory", "devices", "activation", "allocation",
"lvmetad", "metadata", "cache", "locking" ]
# Configuration of metadata backups and archiving. In LVM2 when we
# talk about a 'backup' we mean making a copy of the metadata for the
# *current* system. The 'archive' contains old metadata configurations.
# Backups are stored in a human readable text format.
backup {
# Should we maintain a backup of the current metadata configuration ?
# Use 1 for Yes; 0 for No.
# Think very hard before turning this off!
backup = 1
# Where shall we keep it ?
# Remember to back up this directory regularly!
backup_dir = "/etc/lvm/backup"
# Should we maintain an archive of old metadata configurations.
# Use 1 for Yes; 0 for No.
# On by default. Think very hard before turning this off.
archive = 1
# Where should archived files go ?
# Remember to back up this directory regularly!
archive_dir = "/etc/lvm/archive"
# What is the minimum number of archive files you wish to keep ?
retain_min = 10
# What is the minimum time you wish to keep an archive file for ?
retain_days = 30
# Settings for the running LVM2 in shell (readline) mode.
shell {
# Number of lines of history to store in ~/.lvm_history
history_size = 100
# Miscellaneous global LVM2 settings
global {
# The file creation mask for any files and directories created.
# Interpreted as octal if the first digit is zero.
umask = 077
# Allow other users to read the files
#umask = 022
# Enabling test mode means that no changes to the on disk metadata
# will be made. Equivalent to having the -t option on every
# command. Defaults to off.
test = 0
# Default value for --units argument
units = "h"
# Since version 2.02.54, the tools distinguish between powers of
# 1024 bytes (e.g. KiB, MiB, GiB) and powers of 1000 bytes (e.g.
# KB, MB, GB).
# If you have scripts that depend on the old behaviour, set this to 0
# temporarily until you update them.
si_unit_consistency = 1
# Whether or not to display unit suffix for sizes. This setting has
# no effect if the units are in human-readable form (global/units="h")
# in which case the suffix is always displayed.
suffix = 1
# Whether or not to communicate with the kernel device-mapper.
# Set to 0 if you want to use the tools to manipulate LVM metadata
# without activating any logical volumes.
# If the device-mapper kernel driver is not present in your kernel
# setting this to 0 should suppress the error messages.
activation = 1
# If we can't communicate with device-mapper, should we try running
# the LVM1 tools?
# This option only applies to 2.4 kernels and is provided to help you
# switch between device-mapper kernels and LVM1 kernels.
# The LVM1 tools need to be installed with .lvm1 suffices
# e.g. vgscan.lvm1 and they will stop working after you start using
# the new lvm2 on-disk metadata format.
# The default value is set when the tools are built.
# fallback_to_lvm1 = 0
# The default metadata format that commands should use - "lvm1" or "lvm2".
# The command line override is -M1 or -M2.
# Defaults to "lvm2".
# format = "lvm2"
# Location of proc filesystem
proc = "/proc"
# Type of locking to use. Defaults to local file-based locking (1).
# Turn locking off by setting to 0 (dangerous: risks metadata corruption
# if LVM2 commands get run concurrently).
# Type 2 uses the external shared library locking_library.
# Type 3 uses built-in clustered locking.
# Type 4 uses read-only locking which forbids any operations that might
# change metadata.
# N.B. Don't use lvmetad with locking type 3 as lvmetad is not yet
# supported in clustered environment. If use_lvmetad=1 and locking_type=3
# is set at the same time, LVM always issues a warning message about this
# and then it automatically disables lvmetad use.
locking_type = 1
# Set to 0 to fail when a lock request cannot be satisfied immediately.
wait_for_locks = 1
# If using external locking (type 2) and initialisation fails,
# with this set to 1 an attempt will be made to use the built-in
# clustered locking.
# If you are using a customised locking_library you should set this to 0.
fallback_to_clustered_locking = 1
# If an attempt to initialise type 2 or type 3 locking failed, perhaps
# because cluster components such as clvmd are not running, with this set
# to 1 an attempt will be made to use local file-based locking (type 1).
# If this succeeds, only commands against local volume groups will proceed.
# Volume Groups marked as clustered will be ignored.
fallback_to_local_locking = 1
# Local non-LV directory that holds file-based locks while commands are
# in progress. A directory like /tmp that may get wiped on reboot is OK.
locking_dir = "/run/lock/lvm"
# Whenever there are competing read-only and read-write access requests for
# a volume group's metadata, instead of always granting the read-only
# requests immediately, delay them to allow the read-write requests to be
# serviced. Without this setting, write access may be stalled by a high
# volume of read-only requests.
# NB. This option only affects locking_type = 1 viz. local file-based
# locking.
prioritise_write_locks = 1
# Other entries can go here to allow you to load shared libraries
# e.g. if support for LVM1 metadata was compiled as a shared library use
# format_libraries = "liblvm2format1.so"
# Full pathnames can be given.
# Search this directory first for shared libraries.
# library_dir = "/lib"
# The external locking library to load if locking_type is set to 2.
# locking_library = "liblvm2clusterlock.so"
# Treat any internal errors as fatal errors, aborting the process that
# encountered the internal error. Please only enable for debugging.
abort_on_internal_errors = 0
# Check whether CRC is matching when parsed VG is used multiple times.
# This is useful to catch unexpected internal cached volume group
# structure modification. Please only enable for debugging.
detect_internal_vg_cache_corruption = 0
# If set to 1, no operations that change on-disk metadata will be permitted.
# Additionally, read-only commands that encounter metadata in need of repair
# will still be allowed to proceed exactly as if the repair had been
# performed (except for the unchanged vg_seqno).
# Inappropriate use could mess up your system, so seek advice first!
metadata_read_only = 0
# 'mirror_segtype_default' defines which segtype will be used when the
# shorthand '-m' option is used for mirroring. The possible options are:
# "mirror" - The original RAID1 implementation provided by LVM2/DM. It is
# characterized by a flexible log solution (core, disk, mirrored)
# and by the necessity to block I/O while reconfiguring in the
# event of a failure.
# There is an inherent race in the dmeventd failure handling
# logic with snapshots of devices using this type of RAID1 that
# in the worst case could cause a deadlock.
# Ref: https://bugzilla.redhat.com/show_bug.cgi?id=817130#c10
# "raid1" - This implementation leverages MD's RAID1 personality through
# device-mapper. It is characterized by a lack of log options.
# (A log is always allocated for every device and they are placed
# on the same device as the image - no separate devices are
# required.) This mirror implementation does not require I/O
# to be blocked in the kernel in the event of a failure.
# This mirror implementation is not cluster-aware and cannot be
# used in a shared (active/active) fashion in a cluster.
# Specify the '--type <mirror|raid1>' option to override this default
# setting.
mirror_segtype_default = "raid1"
# 'raid10_segtype_default' determines the segment types used by default
# when the '--stripes/-i' and '--mirrors/-m' arguments are both specified
# during the creation of a logical volume.
# Possible settings include:
# "raid10" - This implementation leverages MD's RAID10 personality through
# device-mapper.
# "mirror" - LVM will layer the 'mirror' and 'stripe' segment types. It
# will do this by creating a mirror on top of striped sub-LVs;
# effectively creating a RAID 0+1 array. This is suboptimal
# in terms of providing redundancy and performance. Changing to
# this setting is not advised.
# Specify the '--type <raid10|mirror>' option to override this default
# setting.
raid10_segtype_default = "raid10"
# The default format for displaying LV names in lvdisplay was changed
# in version 2.02.89 to show the LV name and path separately.
# Previously this was always shown as /dev/vgname/lvname even when that
# was never a valid path in the /dev filesystem.
# Set to 1 to reinstate the previous format.
# lvdisplay_shows_full_device_path = 0
# Whether to use (trust) a running instance of lvmetad. If this is set to
# 0, all commands fall back to the usual scanning mechanisms. When set to 1
# *and* when lvmetad is running (automatically instantiated by making use of
# systemd's socket-based service activation or run as an initscripts service
# or run manually), the volume group metadata and PV state flags are obtained
# from the lvmetad instance and no scanning is done by the individual
# commands. In a setup with lvmetad, lvmetad udev rules *must* be set up for
# LVM to work correctly. Without proper udev rules, all changes in block
# device configuration will be *ignored* until a manual 'pvscan --cache'
# is performed. These rules are installed by default.
# If lvmetad has been running while use_lvmetad was 0, it MUST be stopped
# before changing use_lvmetad to 1 and started again afterwards.
# If using lvmetad, the volume activation is also switched to automatic
# event-based mode. In this mode, the volumes are activated based on
# incoming udev events that automatically inform lvmetad about new PVs
# that appear in the system. Once the VG is complete (all the PVs are
# present), it is auto-activated. The activation/auto_activation_volume_list
# setting controls which volumes are auto-activated (all by default).
# A note about device filtering while lvmetad is used:
# When lvmetad is updated (either automatically based on udev events
# or directly by pvscan --cache <device> call), the devices/filter
# is ignored and all devices are scanned by default. The lvmetad always
# keeps unfiltered information which is then provided to LVM commands
# and then each LVM command does the filtering based on devices/filter
# setting itself.
# To prevent scanning devices completely, even when using lvmetad,
# the devices/global_filter must be used.
# N.B. Don't use lvmetad with locking type 3 as lvmetad is not yet
# supported in clustered environment. If use_lvmetad=1 and locking_type=3
# is set at the same time, LVM always issues a warning message about this
# and then it automatically disables lvmetad use.
use_lvmetad = 0
# Full path of the utility called to check that a thin metadata device
# is in a state that allows it to be used.
# Each time a thin pool needs to be activated or after it is deactivated
# this utility is executed. The activation will only proceed if the utility
# has an exit status of 0.
# Set to "" to skip this check. (Not recommended.)
# The thin tools are available as part of the device-mapper-persistent-data
# package from https://github.com/jthornber/thin-provisioning-tools.
# thin_check_executable = "/usr/bin/thin_check"
# Array of string options passed with thin_check command. By default,
# option "-q" is for quiet output.
# With thin_check version 2.1 or newer you can add "--ignore-non-fatal-errors"
# to let it pass through ignorable errors and fix them later.
# thin_check_options = [ "-q" ]
# Full path of the utility called to repair a thin metadata device
# is in a state that allows it to be used.
# Each time a thin pool needs repair this utility is executed.
# See thin_check_executable how to obtain binaries.
# thin_repair_executable = "/usr/bin/thin_repair"
# Array of extra string options passed with thin_repair command.
# thin_repair_options = [ "" ]
# Full path of the utility called to dump thin metadata content.
# See thin_check_executable how to obtain binaries.
# thin_dump_executable = "/usr/bin/thin_dump"
# If set, given features are not used by thin driver.
# This can be helpful not just for testing, but i.e. allows to avoid
# using problematic implementation of some thin feature.
# Features:
# block_size
# discards
# discards_non_power_2
# external_origin
# metadata_resize
# external_origin_extend
# thin_disabled_features = [ "discards", "block_size" ]
activation {
# Set to 1 to perform internal checks on the operations issued to
# libdevmapper. Useful for debugging problems with activation.
# Some of the checks may be expensive, so it's best to use this
# only when there seems to be a problem.
checks = 0
# Set to 0 to disable udev synchronisation (if compiled into the binaries).
# Processes will not wait for notification from udev.
# They will continue irrespective of any possible udev processing
# in the background. You should only use this if udev is not running
# or has rules that ignore the devices LVM2 creates.
# The command line argument --nodevsync takes precedence over this setting.
# If set to 1 when udev is not running, and there are LVM2 processes
# waiting for udev, run 'dmsetup udevcomplete_all' manually to wake them up.
udev_sync = 1
# Set to 0 to disable the udev rules installed by LVM2 (if built with
# --enable-udev_rules). LVM2 will then manage the /dev nodes and symlinks
# for active logical volumes directly itself.
# N.B. Manual intervention may be required if this setting is changed
# while any logical volumes are active.
udev_rules = 1
# Set to 1 for LVM2 to verify operations performed by udev. This turns on
# additional checks (and if necessary, repairs) on entries in the device
# directory after udev has completed processing its events.
# Useful for diagnosing problems with LVM2/udev interactions.
verify_udev_operations = 0
# If set to 1 and if deactivation of an LV fails, perhaps because
# a process run from a quick udev rule temporarily opened the device,
# retry the operation for a few seconds before failing.
retry_deactivation = 1
# How to fill in missing stripes if activating an incomplete volume.
# Using "error" will make inaccessible parts of the device return
# I/O errors on access. You can instead use a device path, in which
# case, that device will be used to in place of missing stripes.
# But note that using anything other than "error" with mirrored
# or snapshotted volumes is likely to result in data corruption.
missing_stripe_filler = "error"
# The linear target is an optimised version of the striped target
# that only handles a single stripe. Set this to 0 to disable this
# optimisation and always use the striped target.
use_linear_target = 1
# How much stack (in KB) to reserve for use while devices suspended
# Prior to version 2.02.89 this used to be set to 256KB
reserved_stack = 64
# How much memory (in KB) to reserve for use while devices suspended
reserved_memory = 8192
# Nice value used while devices suspended
process_priority = -18
# If volume_list is defined, each LV is only activated if there is a
# match against the list.
# "vgname" and "vgname/lvname" are matched exactly.
# "@tag" matches any tag set in the LV or VG.
# "@*" matches if any tag defined on the host is also set in the LV or VG
# If any host tags exist but volume_list is not defined, a default
# single-entry list containing "@*" is assumed.
# volume_list = [ "vg1", "vg2/lvol1", "@tag1", "@*" ]
# If auto_activation_volume_list is defined, each LV that is to be
# activated with the autoactivation option (--activate ay/-a ay) is
# first checked against the list. There are two scenarios in which
# the autoactivation option is used:
# - automatic activation of volumes based on incoming PVs. If all the
# PVs making up a VG are present in the system, the autoactivation
# is triggered. This requires lvmetad (global/use_lvmetad=1) and udev
# to be running. In this case, "pvscan --cache -aay" is called
# automatically without any user intervention while processing
# udev events. Please, make sure you define auto_activation_volume_list
# properly so only the volumes you want and expect are autoactivated.
# - direct activation on command line with the autoactivation option.
# In this case, the user calls "vgchange --activate ay/-a ay" or
# "lvchange --activate ay/-a ay" directly.
# By default, the auto_activation_volume_list is not defined and all
# volumes will be activated either automatically or by using --activate ay/-a ay.
# N.B. The "activation/volume_list" is still honoured in all cases so even
# if the VG/LV passes the auto_activation_volume_list, it still needs to
# pass the volume_list for it to be activated in the end.
# If auto_activation_volume_list is defined but empty, no volumes will be
# activated automatically and --activate ay/-a ay will do nothing.
# auto_activation_volume_list = []
# If auto_activation_volume_list is defined and it's not empty, only matching
# volumes will be activated either automatically or by using --activate ay/-a ay.
# "vgname" and "vgname/lvname" are matched exactly.
# "@tag" matches any tag set in the LV or VG.
# "@*" matches if any tag defined on the host is also set in the LV or VG
# auto_activation_volume_list = [ "vg1", "vg2/lvol1", "@tag1", "@*" ]
# If read_only_volume_list is defined, each LV that is to be activated
# is checked against the list, and if it matches, it as activated
# in read-only mode. (This overrides '--permission rw' stored in the
# metadata.)
# "vgname" and "vgname/lvname" are matched exactly.
# "@tag" matches any tag set in the LV or VG.
# "@*" matches if any tag defined on the host is also set in the LV or VG
# read_only_volume_list = [ "vg1", "vg2/lvol1", "@tag1", "@*" ]
# Each LV can have an 'activation skip' flag stored persistently against it.
# During activation, this flag is used to decide whether such an LV is skipped.
# The 'activation skip' flag can be set during LV creation and by default it
# is automatically set for thin snapshot LVs. The 'auto_set_activation_skip'
# enables or disables this automatic setting of the flag while LVs are created.
# auto_set_activation_skip = 1
# For RAID or 'mirror' segment types, 'raid_region_size' is the
# size (in KiB) of each:
# - synchronization operation when initializing
# - each copy operation when performing a 'pvmove' (using 'mirror' segtype)
# This setting has replaced 'mirror_region_size' since version 2.02.99
raid_region_size = 512
# Setting to use when there is no readahead value stored in the metadata.
# "none" - Disable readahead.
# "auto" - Use default value chosen by kernel.
readahead = "auto"
# 'raid_fault_policy' defines how a device failure in a RAID logical
# volume is handled. This includes logical volumes that have the following
# segment types: raid1, raid4, raid5*, and raid6*.
# In the event of a failure, the following policies will determine what
# actions are performed during the automated response to failures (when
# dmeventd is monitoring the RAID logical volume) and when 'lvconvert' is
# called manually with the options '--repair' and '--use-policies'.
# "warn" - Use the system log to warn the user that a device in the RAID
# logical volume has failed. It is left to the user to run
# 'lvconvert --repair' manually to remove or replace the failed
# device. As long as the number of failed devices does not
# exceed the redundancy of the logical volume (1 device for
# raid4/5, 2 for raid6, etc) the logical volume will remain
# usable.
# "allocate" - Attempt to use any extra physical volumes in the volume
# group as spares and replace faulty devices.
raid_fault_policy = "warn"
# 'mirror_image_fault_policy' and 'mirror_log_fault_policy' define
# how a device failure affecting a mirror (of "mirror" segment type) is
# handled. A mirror is composed of mirror images (copies) and a log.
# A disk log ensures that a mirror does not need to be re-synced
# (all copies made the same) every time a machine reboots or crashes.
# In the event of a failure, the specified policy will be used to determine
# what happens. This applies to automatic repairs (when the mirror is being
# monitored by dmeventd) and to manual lvconvert --repair when
# --use-policies is given.
# "remove" - Simply remove the faulty device and run without it. If
# the log device fails, the mirror would convert to using
# an in-memory log. This means the mirror will not
# remember its sync status across crashes/reboots and
# the entire mirror will be re-synced. If a
# mirror image fails, the mirror will convert to a
# non-mirrored device if there is only one remaining good
# copy.
# "allocate" - Remove the faulty device and try to allocate space on
# a new device to be a replacement for the failed device.
# Using this policy for the log is fast and maintains the
# ability to remember sync state through crashes/reboots.
# Using this policy for a mirror device is slow, as it
# requires the mirror to resynchronize the devices, but it
# will preserve the mirror characteristic of the device.
# This policy acts like "remove" if no suitable device and
# space can be allocated for the replacement.
# "allocate_anywhere" - Not yet implemented. Useful to place the log device
# temporarily on same physical volume as one of the mirror
# images. This policy is not recommended for mirror devices
# since it would break the redundant nature of the mirror. This
# policy acts like "remove" if no suitable device and space can
# be allocated for the replacement.
mirror_log_fault_policy = "allocate"
mirror_image_fault_policy = "remove"
# 'snapshot_autoextend_threshold' and 'snapshot_autoextend_percent' define
# how to handle automatic snapshot extension. The former defines when the
# snapshot should be extended: when its space usage exceeds this many
# percent. The latter defines how much extra space should be allocated for
# the snapshot, in percent of its current size.
# For example, if you set snapshot_autoextend_threshold to 70 and
# snapshot_autoextend_percent to 20, whenever a snapshot exceeds 70% usage,
# it will be extended by another 20%. For a 1G snapshot, using up 700M will
# trigger a resize to 1.2G. When the usage exceeds 840M, the snapshot will
# be extended to 1.44G, and so on.
# Setting snapshot_autoextend_threshold to 100 disables automatic
# extensions. The minimum value is 50 (A setting below 50 will be treated
# as 50).
snapshot_autoextend_threshold = 100
snapshot_autoextend_percent = 20
# 'thin_pool_autoextend_threshold' and 'thin_pool_autoextend_percent' define
# how to handle automatic pool extension. The former defines when the
# pool should be extended: when its space usage exceeds this many
# percent. The latter defines how much extra space should be allocated for
# the pool, in percent of its current size.
# For example, if you set thin_pool_autoextend_threshold to 70 and
# thin_pool_autoextend_percent to 20, whenever a pool exceeds 70% usage,
# it will be extended by another 20%. For a 1G pool, using up 700M will
# trigger a resize to 1.2G. When the usage exceeds 840M, the pool will
# be extended to 1.44G, and so on.
# Setting thin_pool_autoextend_threshold to 100 disables automatic
# extensions. The minimum value is 50 (A setting below 50 will be treated
# as 50).
thin_pool_autoextend_threshold = 100
thin_pool_autoextend_percent = 20
# While activating devices, I/O to devices being (re)configured is
# suspended, and as a precaution against deadlocks, LVM2 needs to pin
# any memory it is using so it is not paged out. Groups of pages that
# are known not to be accessed during activation need not be pinned
# into memory. Each string listed in this setting is compared against
# each line in /proc/self/maps, and the pages corresponding to any
# lines that match are not pinned. On some systems locale-archive was
# found to make up over 80% of the memory used by the process.
# mlock_filter = [ "locale/locale-archive", "gconv/gconv-modules.cache" ]
# Set to 1 to revert to the default behaviour prior to version 2.02.62
# which used mlockall() to pin the whole process's memory while activating
# devices.
use_mlockall = 0
# Monitoring is enabled by default when activating logical volumes.
# Set to 0 to disable monitoring or use the --ignoremonitoring option.
monitoring = 1
# When pvmove or lvconvert must wait for the kernel to finish
# synchronising or merging data, they check and report progress
# at intervals of this number of seconds. The default is 15 seconds.
# If this is set to 0 and there is only one thing to wait for, there
# are no progress reports, but the process is awoken immediately the
# operation is complete.
polling_interval = 15
# Report settings.
# report {
# Align columns on report output.
# aligned=1
# When buffered reporting is used, the report's content is appended
# incrementally to include each object being reported until the report
# is flushed to output which normally happens at the end of command
# execution. Otherwise, if buffering is not used, each object is
# reported as soon as its processing is finished.
# buffered=1
# Show headings for columns on report.
# headings=1
# A separator to use on report after each field.
# separator=" "
# Use a field name prefix for each field reported.
# prefixes=0
# Quote field values when using field name prefixes.
# quoted=1
# Output each column as a row. If set, this also implies report/prefixes=1.
# colums_as_rows=0
# Comma separated list of columns to sort by when reporting 'lvm devtypes' command.
# See 'lvm devtypes -o help' for the list of possible fields.
# devtypes_sort="devtype_name"
# Comma separated list of columns to report for 'lvm devtypes' command.
# See 'lvm devtypes -o help' for the list of possible fields.
# devtypes_cols="devtype_name,devtype_max_partitions,devtype_description"
# Comma separated list of columns to report for 'lvm devtypes' command in verbose mode.
# See 'lvm devtypes -o help' for the list of possible fields.
# devtypes_cols_verbose="devtype_name,devtype_max_partitions,devtype_description"
# Comma separated list of columns to sort by when reporting 'lvs' command.
# See 'lvs -o help' for the list of possible fields.
# lvs_sort="vg_name,lv_name"
# Comma separated list of columns to report for 'lvs' command.
# See 'lvs -o help' for the list of possible fields.
# lvs_cols="lv_name,vg_name,lv_attr,lv_size,pool_lv,origin,data_percent,move_pv,mirror_log,copy_percent,convert_lv"
# Comma separated list of columns to report for 'lvs' command in verbose mode.
# See 'lvs -o help' for the list of possible fields.
# lvs_cols_verbose="lv_name,vg_name,seg_count,lv_attr,lv_size,lv_major,lv_minor,lv_kernel_major,lv_kernel_minor,pool_lv,origin,data_percent,metadata_percent,move_pv,copy_percent,mirror_log,convert
# Comma separated list of columns to sort by when reporting 'vgs' command.
# See 'vgs -o help' for the list of possible fields.
# vgs_sort="vg_name"
# Comma separated list of columns to report for 'vgs' command.
# See 'vgs -o help' for the list of possible fields.
# vgs_cols="vg_name,pv_count,lv_count,snap_count,vg_attr,vg_size,vg_free"
# Comma separated list of columns to report for 'vgs' command in verbose mode.
# See 'vgs -o help' for the list of possible fields.
# vgs_cols_verbose="vg_name,vg_attr,vg_extent_size,pv_count,lv_count,snap_count,vg_size,vg_free,vg_uuid,vg_profile"
# Comma separated list of columns to sort by when reporting 'pvs' command.
# See 'pvs -o help' for the list of possible fields.
# pvs_sort="pv_name"
# Comma separated list of columns to report for 'pvs' command.
# See 'pvs -o help' for the list of possible fields.
# pvs_cols="pv_name,vg_name,pv_fmt,pv_attr,pv_size,pv_free"
# Comma separated list of columns to report for 'pvs' command in verbose mode.
# See 'pvs -o help' for the list of possible fields.
# pvs_cols_verbose="pv_name,vg_name,pv_fmt,pv_attr,pv_size,pv_free,dev_size,pv_uuid"
# Comma separated list of columns to sort by when reporting 'lvs --segments' command.
# See 'lvs --segments -o help' for the list of possible fields.
# segs_sort="vg_name,lv_name,seg_start"
# Comma separated list of columns to report for 'lvs --segments' command.
# See 'lvs --segments -o help' for the list of possible fields.
# segs_cols="lv_name,vg_name,lv_attr,stripes,segtype,seg_size"
# Comma separated list of columns to report for 'lvs --segments' command in verbose mode.
# See 'lvs --segments -o help' for the list of possible fields.
# segs_cols_verbose="lv_name,vg_name,lv_attr,seg_start,seg_size,stripes,segtype,stripesize,chunksize"
# Comma separated list of columns to sort by when reporting 'pvs --segments' command.
# See 'pvs --segments -o help' for the list of possible fields.
# pvsegs_sort="pv_name,pvseg_start"
# Comma separated list of columns to sort by when reporting 'pvs --segments' command.
# See 'pvs --segments -o help' for the list of possible fields.
# pvsegs_cols="pv_name,vg_name,pv_fmt,pv_attr,pv_size,pv_free,pvseg_start,pvseg_size"
# Comma separated list of columns to sort by when reporting 'pvs --segments' command in verbose mode.
# See 'pvs --segments -o help' for the list of possible fields.
# pvsegs_cols_verbose="pv_name,vg_name,pv_fmt,pv_attr,pv_size,pv_free,pvseg_start,pvseg_size,lv_name,seg_start_pe,segtype,seg_pe_ranges"
# Advanced section #
# Metadata settings
# metadata {
# Default number of copies of metadata to hold on each PV. 0, 1 or 2.
# You might want to override it from the command line with 0
# when running pvcreate on new PVs which are to be added to large VGs.
# pvmetadatacopies = 1
# Default number of copies of metadata to maintain for each VG.
# If set to a non-zero value, LVM automatically chooses which of
# the available metadata areas to use to achieve the requested
# number of copies of the VG metadata. If you set a value larger
# than the the total number of metadata areas available then
# metadata is stored in them all.
# The default value of 0 ("unmanaged") disables this automatic
# management and allows you to control which metadata areas
# are used at the individual PV level using 'pvchange
# --metadataignore y/n'.
# vgmetadatacopies = 0
# Approximate default size of on-disk metadata areas in sectors.
# You should increase this if you have large volume groups or
# you want to retain a large on-disk history of your metadata changes.
# pvmetadatasize = 255
# List of directories holding live copies of text format metadata.
# These directories must not be on logical volumes!
# It's possible to use LVM2 with a couple of directories here,
# preferably on different (non-LV) filesystems, and with no other
# on-disk metadata (pvmetadatacopies = 0). Or this can be in
# addition to on-disk metadata areas.
# The feature was originally added to simplify testing and is not
# supported under low memory situations - the machine could lock up.
# Never edit any files in these directories by hand unless you
# you are absolutely sure you know what you are doing! Use
# the supplied toolset to make changes (e.g. vgcfgrestore).
# dirs = [ "/etc/lvm/metadata", "/mnt/disk2/lvm/metadata2" ]
# Event daemon
dmeventd {
# mirror_library is the library used when monitoring a mirror device.
# "libdevmapper-event-lvm2mirror.so" attempts to recover from
# failures. It removes failed devices from a volume group and
# reconfigures a mirror as necessary. If no mirror library is
# provided, mirrors are not monitored through dmeventd.
mirror_library = "libdevmapper-event-lvm2mirror.so"
# snapshot_library is the library used when monitoring a snapshot device.
# "libdevmapper-event-lvm2snapshot.so" monitors the filling of
# snapshots and emits a warning through syslog when the use of
# the snapshot exceeds 80%. The warning is repeated when 85%, 90% and
# 95% of the snapshot is filled.
snapshot_library = "libdevmapper-event-lvm2snapshot.so"
# thin_library is the library used when monitoring a thin device.
# "libdevmapper-event-lvm2thin.so" monitors the filling of
# pool and emits a warning through syslog when the use of
# the pool exceeds 80%. The warning is repeated when 85%, 90% and
# 95% of the pool is filled.
thin_library = "libdevmapper-event-lvm2thin.so"
# Full path of the dmeventd binary.
# executable = "/usr/sbin/dmeventd" -
What is best use of 1400 gb SGA (2 rac nodes 768gb each)
currently using 11.2.0.3.0 on unix sun sever with 2 RAC nodes each 8 UltraSPARC-T1 cpus (came out in 2005) four threads each so oracle sees 32 CPUS very slow(1.2 gb). Database is 4TB in size on regular SAN (10k speed).
8gb SGA.
New boss wants to update system to the max to get best performance possible Money is a concern of course but budget is pretty high, Our use case is 12-16 users at same time, running reports some small others very large (return single row or 10000s or rows). reports take 5 sec to 5 minutes, Our job is get the fastest system possible, We have total of 8 licenses available so we can have 16 cores. We are also getting a 6tb all flash SSD array for database. we can get any CPU we want but we cant use parallel query server due to all kinds of issues we have experienced (too many slaves, RAC interconnect saturation etc, whack-a-mole). sparc has too many threads and without PS oracle runs query in single thread.
we have speced out the following system for each RAC node
HP ProLiant DL380p Gen8 8 SFF server
2 Intel Xeon E5-2637v2 3.5GHz/4-core cpus
768 gb ram
2 HP 300GB 6G SAS 15K drives for database software
this will give us total of 4 Xeon E5-2637v2 cpus 16 cores total (,5 factor for 8 licenses) and 1536 ram (leaving ~1400 for sga). this will guarantee an available core for each user. we intend to create very very large keep pool around 300 gb for each node that will hold all our dimension tables. this we hope will reduce reads from the SSD to just data from fact tables.,
Are we doing a massive overkill here? the budget for this was way less than what our boss expected. will that big an sga be wasted will say a 256gb be fine. or will oracle take advantage of it and be able to keep most blocks in there.
will an sga that big cause oracle problems due to overhead of handling that much ram?Current System:
===========
a. Version : 11.2.0.3
b. Unix Sun
c. CPU - 8 cpus with 4 threads => 32 logical cpus or cores
d. database 4TB
e. SAN - 10k speed disk drives
f. 8gb SGA
g. 1.2 gb ??
h. Users --> 12-16 concurrent and run reports varying size
i. reports elasped time 5 sec to 5 mins
j. cpu license -->8
Target System
===========
a. Version: 11.2.0.3
b. HP ProLiant DL380p Gen8 8 SFF server
c. RAM --> 768 GB
d. 2 HP 300GB 6G SAS 15K drives for database software
e. large keep pool -->90 gb to hold all dimension tables.
f. SSD to just data from fact tables
g. SGA -->256gb
Reassessment of the performance issues of current system appears to be required.Good performance tuning expert is required to look into tuning issues of current application by analyzing awr performance metrics . If 8GB SGA is not enough,then reason behind so is that queries running in the system are not having good access path to select lesser data to avoid flushing out of recent buffers from different tables involved in the query. Until those issues are identified , wherever you go, performance issue wont be going away as table size increase in future , problem will reappear.Even if the queries are running with more FULL Scan , then re-platforming to Exadata might be right decision as Exadata has smart scan , cell offloading feature which works faster and might be right direction for best performance and best investment for future.Compression (compress for OLTP) could be one of the other feature to exploit to improve further efficiency while reading the lesser block in lesser read time.
Investment in infrastructure will solve a few issue in short term but long term issue will again arise.
Investment in identifying the performance issues of current system would be best investment in current scenario. -
How to create a temp table in the memory, not in disk?
in sql server, you can create a temp table in the memory instead of disk,
then you can do the insert, delete,update and select on it.
after finishing, just release it.
in Oracle,
I am wonderfing how to create a temp table in the memory, not in disk?
thanks,Thanks for rectifying me Howard.
I just read your full article on this too and its very well explained here:
http://www.dizwell.com/prod/node/357
Few lines from your article
It is true, of course, that since Version 8.0 Oracle has provided the ability to create a Keep Pool in the Buffer Cache, which certainly sounds like it can do the job... especially since that word 'keep' is used again. But a keep pool is merely a segregated part of the buffer cache, into which you direct blocks from particular tables (by creating them, or altering them, with the BUFFER POOL KEEP clause). So you can tuck the blocks from such tables out of the way, into their own part of the buffer cache... but that is not the same thing as guaranteeing they'll stay there. If you over-populate the Keep Pool, then its LRU mechanism will kick in and age its contents out just as efficiently as an unsegregated buffer cache would.
Functionally, therefore, there can be no guarantees. The best you can do is create a sufficiently large Keep Pool, and then choose the tables that will use it with care such that they don’t swamp themselves, and start causing each other to age out back to disk.
Thanks and Regards -
I'm trying to write up advice for Storage node thread count.
Obviously, this is dependent of the machines - we have 48G 8processor machines, running 20 x2G Storage nodes and 2 x 2G Proxy nodes.
My understand is that when you don't have a cache-store you would set the thread-count to 0 (run on service thread).
I'm wondering how one might calculate this if you have a cache store ( and whether its different if you have write through / behind ).
I can see that in write-through it will spend most of the time with the database and a higher thread count would be good (its a pity its not a variable size pool with min and max).
I'm not sure about write-behind - I can imagine that a low thread count might be reasonable here.
I'm sure Rob (or others ) have a good formula for this.
Best, Andrew.I have a brief recollection (may be wrong about this) that there is some info (via JMX) about average thread pool usage that may be of assistance (if the average is close to your specified max it may pay off to increase it furthe and see if throughput goes up or down, if the average is close to zero it may be just as well to use zero thread count rather than what is used at the moment).
One must also decide what is most important - to max out throughput or to limit median response time. With a larger thread pool more queries can be in progress at the same time (hopefully reducing median responce time since long runing queries dont lock out other queries) but resources will be split between them (at least if the thread count is larger than the number of cores) making the total throughput lower...
/Magnus -
How to cache out the parse plan up front?
Hi,
Basically I have 2 questions:
(1) When you run a query the first time ,it usually takes longer time because Oracle will parse it to get execution plan first. But afterwards, because of caching , it runs faster. How do I set up so that this step can be skipped when user runs first time?
In other words, any standard method to get the query execution plan planed out first and cache it in the Oracle.
(2) Is this cache per session? Can I keep it always in the cache and not cycled out? Also if per session, can I possibly make it per database wise?
Thanks in advance!
Acton1) Perhaps, perhaps not. There are too many variables that can influence execution time. Usually (not always), the parse phase consumes very little of the reponse time. However, I have seen this phase be the #1 contributor to poor response time. If you trace the query, execute it repeatedly, you will be able to see the differences in response time for each phase using tkprof.
You can reuse an execution plan if there is an identical statement in the shared_pool (with certain exceptions if cursor_sharing is set or you are using stored outlines). If the statement does not exist in the shared_pool, it must be 'hard' parsed. Let's assume that neither cursor_sharing nor stored outlines are in use. There is NO way to get around parsing, you must parse to get an execution plan.
Oracle has put a lot of work into making the parse phase efficient. One component of this is how they manage the shared pool. While a large shared pool sounds like you would be able to improve performance by caching all the execution plans, it is usually a bad idea. Let frequently used plans stay in the pool, let one-time or seldom used plans age out. Too many cached statements mean that the session has to search through a lot of 'similar' statements to finally say "Nope, not there, let's parse this statement".
2) You can always keep something in the cache by pinning it. Again, this is not always a good idea (though there are exceptions). Statements and plans are always cached in the shared pool, which are available to all sessions.
Justin - did you mean that the first execution runs slower because the data is NOT cached?
Regards,
Dan Fink -
Hi
We have Oracle RAC 11g2 in windows 2008R2 in two nodes and application 6i an 10g
We use DNS and Scan name resolve to three IP address
for the 10g the operation is acceptable but for 6i is very very slow
any idea!srsatya wrote:
What is the SGA of the DB, I had the same problem, when increased the SGA it was fine. In our case we upgraded DB from 10.2.0.5 to 11gr2, it need min 3gb SGA to quicker response.And why did a larger SGA seemingly resolved your problem? Any ideas?
Do you know that a larger SGA (and thus larger Shared Pool) can actually worsen performance when the system deals with non-bind SQL parsing? Instead of increasing the db buffer cache and increasing potential logical I/O and providing associated performance gains?
Dealing with performance is more than pushing buttons and turning knobs until it is "better"... and then blindly suggested that as a solution for all performance problems.
How about reading Oracle® Database Performance Tuning Guide? And pay special attention to +1.1.2.3 The Symptoms and the Problems+:
>
A common pitfall in performance tuning is to mistake the symptoms of a problem for the actual problem itself. It is important to recognize that many performance statistics indicate the symptoms, and that identifying the symptom is not sufficient data to implement a remedy -
Solaris won't boot after installation on ESX 3.5
Hello everyone,
After installing last Solaris 10 x86 (download last iso from sun site) on a virtual machine on ESX 3.5 does not start at boot because it shuts down without displaying any errors.
Someone has done it? How to set up your vm?
I have already read these documents from Google but have not solved the problem
- http://pubs.vmware.com/guestnotes/wwhelp/wwhimpl/common/html/wwhelp.htm?context=guestnotes&file=guestos_solaris10.html
- http://www.hashpee.com/2009/09/sun-cluster-32-on-esx-35.html
- http://wotho.ethz.ch/ESX_solaris/Install_Solaris_on_ESX.html
Thanks in advance
Edited by: alman64 on Oct 1, 2009 9:20 AMI'm having the EXACT same problem and have found little to help...
I too would like to use ZFS for a larger disk pool, but at this point I am thinking about loading Redhat instead. -
Project server 2013 olap database remains in processing state
Hi,
In an attempt to restore the Reporting Database in Project Server 2013, I did an archive and restore of Custom fields. Both of these events were successful, however, the Reporting database refresh kept on hanging in "Waiting to be processed status".
Before this was noticed, the OLAP Database was configured and a build was initiated. Now the status of the PWAOLAPDatabase build just remains in the "Processing..." status. What am I to do here? Thanks!Hi Jaco,
It seems like your reporting database refresh has failed, so the OLAP DB cannot be generated either. It could be due to a large resource pool.
See reference below:
http://social.technet.microsoft.com/Forums/projectserver/en-US/7ac3bb1b-6621-46f0-a6c5-d9a04f770418/reporting-database-refresh-project-server-2010?forum=projectserver2010general
http://blogs.msdn.com/b/brismith/archive/2011/07/14/project-server-2010-reporting-database-refresh-failing-with-large-resource-pools.aspx
Note also that you can click on "processing" (as per your screenshot) to have the OLAP DB creation log in order to have more information on the status.
Hope this helps,
Guillaume Rouyre, MBA, MCP, MCTS |
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