Redhat 5.2 Kernel Parameters

What file do you update to change the following parameters in
redhat 5.2?
shmmax
shmmni
shmseg
shmmns
semmni
If this is not a system file configuation change how do you do
it?
You just reboot afterwards, correct?
Bob@Zeneca Pharms
null

I am running RedHat 5.2 2.0.36 SMP Dual Pentium Pro 200.
It works great. It recompiled kernel with SMP enabled and PPro
processor in place of i386.
Jaroslaw Sosnicki
Eddy Hahn (guest) wrote:
: I am running an SMP box with RedHat 5.2. Oracle was running on
: it beautifully but since I upgraded my kernel 2.2.1 it even
: FASTER !
: Oracle rocks ...
: Eddy
null

Similar Messages

Kernel parameters problem (512 mb RAM)

Hi,
I've installed Oracle on RedHat 5.2 (2.0.36) on a machine with
512 mb memory.
First I've recompiled the kernel how Oracle says and basing in
some documents (like
http://jordan.fortwayne.com/oracle/oralinux.html). Of course I've
saved a copy of the old kernel. The linux was ok, the command
ipcs -l shows the new values of the kernel parameters, but Oracle
didn't start. I've restored the copy of the kernel, the ipcs -l
shows the old values and now Oracle is running, with a SGA of
almost 300 mb.
Is there some problem in that? Will the machine loose performance
because the miminum values of the kernel parameters?
Best regards,
Ari
null

Ari Arantes (guest) wrote:
: Hi,
: I've installed Oracle on RedHat 5.2 (2.0.36) on a machine with
: 512 mb memory.
: First I've recompiled the kernel how Oracle says and basing in
: some documents (like
: http://jordan.fortwayne.com/oracle/oralinux.html). Of course
I've
: saved a copy of the old kernel. The linux was ok, the command
: ipcs -l shows the new values of the kernel parameters, but
Oracle
: didn't start. I've restored the copy of the kernel, the ipcs -
l
: shows the old values and now Oracle is running, with a SGA of
: almost 300 mb.
: Is there some problem in that? Will the machine loose
performance
: because the miminum values of the kernel parameters?
: Best regards,
: Ari
I have a setup similar to yours (384 MB instead of 512 MB),
and I spent some time looking at the parameters.
You CANNOT use the value for SHMMAX from the Oracle manual!
As it says at http://jordan.fortwayne.com/oracle/oralinux.html
"Should you decided to change these parameters, if you set
the SHMMAX to what Oracle says, you are telling the system
to allow a shared memory segment to grow as large as 4 Gigs.
Many users have reported problems setting the value this
high."
Sounds like you are another one of those users, eh?
If you read on down, the guy who wrote that web page never
used over 128 MB for SHMMAX. I'd take a strong hint from that.
=====
Oracle wants you to use 4GB-1 as the SHMMAX value. That
equates to (1<<32)-1. As we shall see, that is not allowed
without "breaking the rules" for the i386 architecture.
If you carefully read through the header file, you will find
out that the **actual maximum value** for SHMMAX is 256 MB.
You can tell this two ways. Take a look at the file at:
/usr/src/linux/include/asm/shmparam.h
Near the top of the file is:
/* address range for shared memory attaches if
no address passed to shmat() */
#define SHM_RANGE_START 0x50000000
#define SHM_RANGE_END 0x60000000
Note that the above is 256 MB (0x10000000), or (1<<28). This
is one potential source of trouble. I don't know if some other
files someplace else in the kernel specify uses for address
ranges adjacent to the above range, which I take to be the
"practical maximum" without redefining that range. Personally,
I wouldn't want to mess with the above unless I **really**
knew what I was doing (and I'll be the first to admit I don't).
=====
Farther down you will see some more lines (not together)
that look like this:
#define SHMID_BITS 7
#define SHMIDX_BITS 15
* SHMID_BITS + SHMIDX_BITS must be <= 24 on the i386 and
* SHMMAX <= (PAGE_SIZE << SHMIDX_BITS).
#define SHMMAX 0x2000000 /* max shared seg
size (bytes) */
Now, 7 + 15 is 22, so you could go up a couple of bits if you
had to. To avoid making the table any larger, I would suggest:
#define SHMIDX_BITS 17
But, 17 turns out to produce a result larger than the "practical
maximum" (256 MB) above. To see why takes a little more
explaining.
And if you don't change this at all, then the maximum possible
value for SHMMAX is 4096 [the PAGE_SIZE) << 15 [_SHM_IDX_BITS],
or rather (1<<27).
Now, that is exactly half of the (1<<28) "practical maximum" I
mentioned above.
So, if you always want the maximum amount of shared memory,
then change the definition of SHMMAX to the following:
#define SHMMAX (PAGE_SIZE<<_SHM_IDX_BITS) /* max shared seg
size (bytes) */
That gives you 128 MB in and of itself (as compared with 32 MB
as Red Hat 5.2 is delivered).
If you want the full 256 MB that is allowed for in the memory
map, then you need to also change:
#define SHMIDX_BITS 16
The above value is **exactly** what is recommended on the web
page you were following (above).
If you want to keep going up, you will need to change the
memory space allocated for shared memory as defined by
SHM_RANGE_START and SHM_RANGE_END, something I advise against.
=====
Even on a machine with 512 MB of "real" memory, I find it hard
to believe that there would be any substantial benefit to
having a maximum shared memory space greater than 256 MB. The
reason is that Oracle can use multiple shared memory spaces.
It requires a minimum of ten (10), according to the installation
manual, but the Red Hat 5.2 distribution supplies SHMMNI (128)
of them. That will allow each Oracle process to have a total
of up to 32 GB of shared memory (128 times 256 MB) and all it
asks for is 40 GB (10 times 4 GB), so it has plenty, IMHO.
=====
Let me say a few more words about the web page you were using
for configuration advice. That person actually **reduced** the
amount of shared memory segments by specifying **lower values**
for SHMMNI and SHMSEG (not to mention the semaphores).
I'd **STRONGLY** recommend **NOT CHANGING** those other values!
Its my understanding that Oracle can make up for the smaller
maximum shared memory segment size by using more shared memory
segments. So, if you reduce those, you are essentially shooting
yourself in the foot by taking away what you are giving with
increasing the maximum segment size.
=====
Good luck, and may this farce be with you!
null

Unable to set kernel parameters using solaris 10

HI,
I'm trying to install DB2 8.2 on solaris 10.the problem i'm encountering in installation is unable to set MSGMAX and MSGMNB kernel parameters. I tried setting the new replacement parameter process.max-msq-qbytes through projects->Resource Control from the management console.but still uinable to set the parameters.
Can anyone help me in setting the above kernel parameters.
Its not possible to set it thru /etc/system.
thanx
guru

HI,
I'm trying to install DB2 8.2 on solaris 10.the problem i'm encountering in installation is unable to set MSGMAX and MSGMNB kernel parameters. I tried setting the new replacement parameter process.max-msq-qbytes through projects->Resource Control from the management console.but still uinable to set the parameters.
Can anyone help me in setting the above kernel parameters.
Its not possible to set it thru /etc/system.
thanx
guru

Unable to set kernel parameters using Reource Control

HI,
I'm trying to install DB2 8.2 on solaris 10.the problem i'm encountering in installation is unable to set MSGMAX and MSGMNB kernel parameters. I tried setting the new replacement parameter process.max-msq-qbytes through projects->Resource Control from the management console.but still uinable to set the parameters.
Can anyone help me in setting the above kernel parameters.
Its not possible to set it thru /etc/system.
thanx
guru

I finally had some time to find the actual syntax for tuning process.max-msq-qbytes and process.max-msg-messages. prctl will change those paramaters for an existing process.
As a proof of concept I changed process.max-msg-messages to a 64k. process 2221 is my shell.
prctl -n process.max-msg-messages -r -v 64k 2221
bash-3.00# prctl 2221
process: 2221: -csh
NAME    PRIVILEGE       VALUE    FLAG   ACTION                       RECIPIENT
process.max-port-events
        privileged      65.5K       -   deny                                 -
        system          2.15G     max   deny                                 -
process.max-msg-messages
        privileged      64.0K       -   deny                                 -
        system          4.29G     max   deny                                 -
process.max-msg-qbytes
        privileged      64.0KB      -   deny                                 -
        system          4.00GB    max   deny                                 -And now to make this persist across reboots...
So long as I'm experimenting, I'll use projadd and add a new project which just includes me and not the rest of the users in the group staff.
bash-3.00# projadd -p 115 -U testuser \
-K "process.max-msg-messages=(priv,64K,deny)" \
-K "process.max-msg-qbytes=(priv,64K,deny)" \
user.me This creates the following /etc/project:
(note the last line is all on one line in the real file minus the \.)
placer% cat /etc/project
system:0::::
user.root:1::::
noproject:2::::
default:3::::
group.staff:10::::
user.me:115::testme::\
process.max-msg-messages=(priv,64000,deny);process.max-msg-qbytes=(priv,65536,deny)After a reboot I checked the values by loging in under my user and running prctl.
placer% prctl $$
process: 419: -csh
NAME    PRIVILEGE       VALUE    FLAG   ACTION                       RECIPIENT
process.max-port-events
        privileged      65.5K       -   deny                                 -
        system          2.15G     max   deny                                 -
process.max-msg-messages
        privileged      64.0K       -   deny                                 -
        system          4.29G     max   deny                                 -
process.max-msg-qbytes
        privileged      64.0KB      -   deny                                 -
        system          4.00GB    max   deny                                 -
process.max-sem-ops
        privileged        512       -   deny                                 -
        system          2.15G     max   deny                                 -
...Solaris 10 has different tunables and default values from 8 and 9. It's default tunables should be good for most applications per a given system's hardware. There are some great blog articles, and discussions on opensolaris.org and blogs.sun.com on tuning that explain the intent of tuning and why we shouldn't have to tune.
Cheers,
~~sa

Unable to set kernel parameters using Reource Control in solaris 10

HI,
I'm trying to install DB2 8.2 on solaris 10.the problem i'm encountering in installation is unable to set MSGMAX and MSGMNB kernel parameters. I tried setting the new replacement parameter process.max-msq-qbytes through projects->Resource Control from the management console.but still uinable to set the parameters.
Can anyone help me in setting the above kernel parameters.
Its not possible to set it thru /etc/system.
thanx

HI,
I'm trying to install DB2 8.2 on solaris 10.the problem i'm encountering in installation is unable to set MSGMAX and MSGMNB kernel parameters. I tried setting the new replacement parameter process.max-msq-qbytes through projects->Resource Control from the management console.but still uinable to set the parameters.
Can anyone help me in setting the above kernel parameters.
Its not possible to set it thru /etc/system.
thanx

IOMMU explanation of kernel parameters

Hello!
I've set up an HTPC with an AMD A4-5300 CPU, A75 (Hudson-D3) chipset and a PCIe sound card (Asus Xonar DX). Whenever I tried to get a sound out of it (e.g. aplay blubb.wav) I only got dozens of these messages in the kernel log:
[ 46.215678] AMD-Vi: Event logged [IO_PAGE_FAULT device=02:00.0 domain=0x0000 address=0x0000000000100000 flags=0x0050]
The messages appeared only on the first aplay command. When the program finished and I ran it again, I got no additional messages but sadly also no sound.
Spending two evenings on this problem with google I found out it might be some trouble with IOMMU features of the processor or mainboard. So after trying out several of the options, I found iommu=soft in the kernel parameters got the sound to work fine. I have the possible options from here: https://www.kernel.org/doc/Documentatio … ptions.txt
But I don't really understand what's the matter with this IOMMU thing. It seems like a memory management for I/O Components and seems related to DMA access. But what does the IOMMU do? Which side effects come with these options? I understand the "soft" option in that way, that some features present in hardware are now managed in software. "can be used to prevent the of an available hardware IOMMU" sounds even worse since the option might completely disable the hardware feature. But is this really bad? I mean with the option I finally have good quality audio output but for what price? Can I expect disadvantages from this setting? Since I'm not really into all this kernel and hardware stuff, this all seems so confusing. Or is it possible that the error causing the above message has a totally different source and it's just luck that the option kind of worked around it?
Can anyone here maybe explain even a little bit about the IOMMU and what might have caused these problems?
I opened a thread in the multimedia section here where I asked for help to get audio output but no one replied. So I think the people living over there are also not familiar with the topic. And since I found kind of a workaround which is hardware related I hope it is ok to open this other thread to maybe get some explanation about what I have really done there...

Thanks for the detailed explanation!
But isn't the GART something Video Card related? Or is it that what you mean with "abusing" the GART?
So when I set "iommu=soft" the IOMMU basically gets disabled? Quoting the file about the boot options, it says:
3. <arch/x86_64/kernel/pci-swiotlb.c> : Software IOMMU implementation. Used
e.g. if there is no hardware IOMMU in the system and it is need because
you have >3GB memory or told the kernel to us it (iommu=soft))
Kernel boot message: "PCI-DMA: Using software bounce buffering
for IO (SWIOTLB)"
What I don't fully understand... Is the IOMMU actually a CPU feature or is it on the mainboard's hand? For what I read, the A-Processors from AMD are IOMMU supported, so my setup should work with it. Or could it be my mainboard not having correct support for it? (MSI FM2-A75IA-E53)
For testing, I disabled the IOMMU switch in GRUB, dmesg shows the kernel already automatically chooses software buffering. ("[ 0.654086] PCI-DMA: Using software bounce buffering for IO (SWIOTLB)") but then I get those tons of AMD-Vi messages. When I set the IOMMU to force software buffering, I have not a single problem. The entry in dmesg also tells it is using software bounce buffering. But shouldn't there be no difference if the kernel chooses the software option or if I force it to do so?

Where to download OAS9i V1.0.2.2 for Linux RedHat RH6.2(kernel 2.2.16 or later) use?

So that we may better diagnose problems, please provide the following information.
- Server name:linux1
- Filename
- Date/Time: 2/6/2002
- Browser + Version: Netscape 6
- O/S + Version: Linux RedHat 6.2 (Kernel 2.2.19, glibc 2.1.3)
- Error Msg
I am a member of OTN, and I tried to download and test OAS9i for my platform - Linux RedHat 6.2(Kernel 2.2.19, glibc 2.1.3), and I tried to find the related OAS9i product for Linux use from your site "Oracle9iAS Download Options", but I got a confused about those items, I found v1.0.2.2.1 OAS9i image *.cp file there, but there installation guide itself shows that it is for V1.0.2.2 use,that is for Intel Linux use(Kernel 2.2.14 or later, glibc 2.1.3), however, the image *.cp file which could be downloaded is V1.0.2.2.1, is for Intel RH7.1 Linux use(Kernel 2.4.3-12, glibc 2.2.2-10).
So that's very strange, and I want to know that where can I download the *.cp files for Intel Linux RH6.2 use(Kernel 2.2.19 or later, glibc 2.1.3), my platform is RH6.2 because I heart that Intel Linux RedHat's version over 6.2 doesn't be certificated by ORACLE, so I always use Intel RedHat 6.2 as my basic platform, so who can tell me where to download the imgae *.cp files for my platform use? Or any suggestion?
Thanks in advance!
Best Regards!
Frank

You wrote:
There no longer are standalone upgraders for Safari.
I beg to differ, amigo...
...but you're correct in saying that they're not generally available. You have to know where to find them. Evidently, you don't...and obviously I didn't either, or I wouldn't have asked. But I think I know how to find out where they are now.
Thanks again for your prompt replies.

Kernel parameters?

Dear all,
How can I see Kernel parameters in OS or Database level?
Best Regards,
Amy

Issue the following command:
/sbin/sysctl -a | grep sem
Unable to find a file sysctl under /sbin directory, only see the following files:
/sbin
$ ls -lt
total 88
-rwxrwxr-- 1 root system 25036 Nov 01 2004 rc.boot
drwxrwxr-x 3 root system 512 Nov 01 2004 helpers
lrwxrwxrwx 1 root system 34 Jul 04 2003 install-info -> /usr/opt/freeware/bin/install-info
-r-xr-xr-x 1 root system 2746 Sep 19 2002 comp.uext
-r-xr-xr-x 1 root system 3168 Sep 19 2002 comp.kext
-r-xr-xr-x 1 root system 3518 Sep 19 2002 comp.uext64

Kernel parameters -maximum threads per process

How can we change the kernel parameters also how can we increase the maximum number of threads allowed .
How can we increase maimum perocess per used id .

There is no kernel parameter limiting the maximum
number of threads allowed. If you are talking about
user level threads, you will run into virtual address
space limitations at about 3000 for a process
assuming 32-bit address space and default
stack size of 1M per thread, and assuming you are
not using the alternate thread library (see threads(3thr))
or Solaris 9. If you need more than this many
threads at the same time, I suspect you are doing something
incorrectly. Otherwise, try using a smaller stack size
per thread. If you are running on Solaris 9, or using
the alternate thread library, both give you a 1x1
thread model, i.e., each user thread has a corresponding
kernel entity (lwp). In this case, you will cause
your machine to hang by eating up all available
space for lwp's. In either case, the question should be:
"how do I limit the number of threads per process?", since
there is currently no limitation other than space.
In Solaris 9, you can use resource management to
limit the number of lwp's (and therefore user threads)
per process.

Kernel Parameters on Red Hat Linux

The installation instructions require us to set cetain kernel
parameters, such as SHMMAX, SHMSEG, SEMMNS, and so on.
Does anyone know how this is done for Red Hat Linux? I have
been hunting around the documentation and public domain web-
sites for a couple of weeks now and I haven't found any
reference to how to set these parameters.
Eternally grateful for any insights...
Cheers!
Stuart Housden
null

I had problems with 8i and 32Meg of SHMMAX (sometimes, when I
published an EJB, Oracle crashed). I didn't recompiled the
kernel, only did
echo 134217728 > /proc/sys/kernel/shmmax.
This limited the maximum shared memory to 128Meg (I installed
with JavaVM enabled), and I my problems got away.
Robson.
Anwar (guest) wrote:
: Stuart Housden (guest) wrote:
: : The installation instructions require us to set cetain kernel
: : parameters, such as SHMMAX, SHMSEG, SEMMNS, and so on.
: : Does anyone know how this is done for Red Hat Linux? I have
: : been hunting around the documentation and public domain web-
: : sites for a couple of weeks now and I haven't found any
: : reference to how to set these parameters.
: : Eternally grateful for any insights...
: : Cheers!
: : Stuart Housden
: This question was replied to multiple times on the list before,
: but here goes. Check out:
: http://jordan.fortwayne.com/oracle
: Basically, you have to edit the kernel header files, and
: recompile the kernel. Read the Kernel-HOWTO too.
: Anwar.
null

Oracle parameters related kernel parameters

Hi,
Can anyone tell me hwo can i get the info about the oracle parameters which are related to os, for example- i am getting a request to change the process parameter for the db instance which are the kernel parameters need to be changed..
so we have to relate the kernel parameters with database parameters. like this, can i get anywhere for oracle parameters which are associated with kernel parameters. Please let me know if anyone has this information.
Thank u.

990991 wrote:
Hey.. i want to know which oracle parameter is associated with kernel parameters ..
something like this shmmax === related SGA (which exact oracle parameter of SGA need to be changed at database level) similarly for process parameter which parameter is related at os level (in kernel parameters)
I think my question is clear now.. to get the appropriate help.
Thank U..
Did you consider that it is not a one-for-one relationship?
The installation guide is very explicit about how to set the kernel parameters.
Most importantly, what error triggered this request? We often see people chasing the wrong solution for their unstated problems.

Problems Installing Oracle 10GR2 & kernel parameters

Hi there,
I'm trying to install Oracle 10G on a new Solaris10 machine. After extensivley reading the oracle install guide and proceeding my install failed with an out of memory error.
Ive read the posts regarding many similar problems and to set the kernel parameters in /etc/system. My question for the experts is:
1). Is there a problem with the oracle install scripts and it not recognising the new features in Solaris?
2). Is there a more deep-rooted problem with oracle and solaris?
ANY help/advice would be much appreciated. There are hundreds of posts like this on the web and surely someone must have the answer? I mean surely oracle did not hack /etc/system to get their install to work did they??
Nibs

It IS a terrible experince to install oracle 10g on solaris 10. Tell us your system configuration and your installation step. For I have installed three times and each time a different problem. Suggest you go to oracle forum to get more help.

Reg: Kernel Parameters White paper

Hi Gurus,
Can any one tell me the importance of kernel parameters with respect to oracle database installation.
Thanks & Regards
Azim

There is some Oracle specific info at [Solaris Internals and Performance FAQ|http://www.solarisinternals.com/wiki/index.php/Solaris_Internals_and_Performance_FAQ]
Are you looking to solve a problem(s) or just avoid them?
have a good day,
Glen

Calculating Kernel parameters for Oracle 11g R2 db on solaris 10u9

Hi Everyone,
I have query regarding calculating the kernel parameters for deploying oracle 11g R2 db on solaris 10 v 5.10 update 09 machine , we have Ram size of 64gb.
My question is how to calculate shared memory ,shared memory identifiers,semaphores, semaphores identiifiers for creating resource control for the project(user.oracle).
And how to fine out the available semphore values allocated in system..
Thanks in Advance.
Edited by: 898979 on Dec 15, 2011 10:24 PM

Hi;
For those setting mention in installation guide which is already shared previous post.
I suggest also see:
Oracle Database on Unix AIX,HP-UX,Linux,Mac OS X,Solaris,Tru64 Unix Operating Systems Installation and Configuration Requirements Quick Reference (8.0.5 to 11.2) [ID 169706.1]
Regard
Helios

Where are the Linux kernel parameters?

I have successfully installed ORACLE on red hat linux 5.0
even though I didn't set the kernel parameters.
On Solaris these parameters can be set in the /etc/system file.
Where do you set SHMMAX and the kernel parameters in linux?
I could not find a similar file.
Please enlighten me.
Thank You
Be careful with environment variables!
run the root.sh script after installation!
null

Frank Westheider (guest) wrote:
: Mark Lee (guest) wrote:
: : I have successfully installed ORACLE on red hat linux 5.0
: : even though I didn't set the kernel parameters.
: : On Solaris these parameters can be set in the /etc/system
file.
: : Where do you set SHMMAX and the kernel parameters in linux?
: : I could not find a similar file.
: : Please enlighten me.
: : Thank You
: : Be careful with environment variables!
: : run the root.sh script after installation!
: Hi Mark.
: You have to install the Kernel-Sources and Include-Files.
: Just look in
: /usr/include/asm/*shm*.h
: and change the parameters. After this re-create the kernel with
: cd /usr/src/linux
: make clean && make dep && make && make modules && make
: modules_install
: and install the kernel-file (lilo/bootlin....).
: Ciao
: Frank Westheider
You might want to follow this thread (it's on the previous page
of threads):
Kernel Parameters?
From: Bolen Coogler (guest)
Email: [email protected]
Date: Mon Oct 26 16:00 CST 1998
The Oracle install instructions mention setting various kernel
parameters, such as:
SHMMAX 4294967296 (0x100000000)
SHMMIN 1
SHMMNI 100
SHMSEG 10
SEMMNS 200
SEMMNI 70
SEMMSL
While setting these parameters is VERY important in HP/UX or
Solaris, I haven't the slightest idea if this is really applies
to Linux. Does anyone know if tweaking these and other kernel
parameters matters in Linux? If so, where do you make these kind
of changes? (/usr/src/linux/include/linux/<something>.h ?)
My initial impression is the Oracle on Linux documentation is
converted Solaris boilerplate (i.e. %s/Solaris/Linux/g).
null

Redhat 5.2 Kernel Parameters

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