Raw device based database

Have anyone tried to use raw devase base database?
I tried all teh documentation available but could not find
anything about this
If I tell Orecle to create a database on a raw device (like
/dev/sda6), it tries to erase the file. However it should accept
it I suppose. Mounting the device /dev/sda6 under a directory
doesn't help either. Is it normal behaviour and I am missing
something or raw device database structure is not implemented
under Linux yet?
Thanks in advance
null

Nicholas Tufar (guest) wrote:
: Have anyone tried to use raw devase base database?
: I tried all teh documentation available but could not find
: anything about this
: If I tell Orecle to create a database on a raw device (like
: /dev/sda6), it tries to erase the file. However it should
accept
: it I suppose. Mounting the device /dev/sda6 under a directory
: doesn't help either. Is it normal behaviour and I am missing
: something or raw device database structure is not implemented
: under Linux yet?
: Thanks in advance
Linux dosn't support raw devices. Oracle requires symbol
device but in Linux you have only block devices. Also access to
this devices is cached by OS.
null

Similar Messages

Raw Device Validation Check for Name Failed..

Hi all,
I have installed Oracle Clusterware 10.2.0.4 and Oracle database software 10.2.0.4 on Solaris SPARC 10 and i using a NAS storage for the same
And when i try to create a database using DBCA i got the following error.
Raw Device Validation Check for Name /u03/oradata/spfile/spfile{SID}.ora failed. The specified file /u01/oradata/spfile/spfile{SID}.ora doesnot exit.Please a existing file.
Note: i am not using ASM., i am using RAW device for Database
Any help highly thankful
-Arun

Hi
this is how i have mounted the NAS...
10.0.0.0:/vol/prodt3_vol16/ora_dbfr_inn1s - /u07/DBFR/INS nfs - yes rw,bg,hard,nointr,rsize=32768,wsize=32768,proto=tcp,noac,forcedirectio,vers=3,suid
how do i ensure that it is not being used....we should not use ASM its an client requinment ...
Thanks

Raw devices files

Hi,
I already created raw devices on database 10g R2. How can make those raw devices available to oracle user?
Best Regards
Yassin
Message was edited by:
Yassin

Yes, the os is Sun Solaris and my question how can
create tablespaces on raw devices.create tablespace abcd datafile '/dev/rdsk/c0t0d0s4/abcd.dbf' size ...
This is an example only, adapt it to your needs! Never fill up the rawdevice completely, leave some space for emergency situations. A different question: why are you using raw devices? What's the output of uname -a? Beginning with Solaris 8 (don't know the maintenance level), you can mount filesystems with the direct io option which gives you almost raw device performance with all advantages of a file system.
Thank you.
Yassin
Message was edited by:
Yassin

Convert Raw Device to file system based file systems for datafiles [HP-UX]

Hello experts,
Once again in seek of guidance..
I am in the process of migrating my database (Oracle 7.2.3 on HP-UX 10.20 to Oracle 8.1.7 64-bits on HP-UX 11).
Amongst one of our steps is to convert our RAW Device datafiles to File System based files within the same server and version - Oracle 7.2.3 on HP-UX 10.20.
E.g. /dev/vg00/rlvol1 to become /d01/oradata/cmtdb/tbs1.dbf
Is this something possible?
Can i just do the following:
a. Shutdown database (normal)
b. dd if=/dev/vg00/rlvol1 of=/d01/oradata/cmtdb/tbs1.dbf bs=20k
c. chown oracle7:dba /d01/oradata/cmtdb/tbs1.dbf
d. svrmgrl> startup mount
e. alter database rename file '/dev/vg00/rlvol1' to '/d01/oradata/cmtdb/tbs1.dbf'
f. alter database open.
Thanks very much for your replies.
Please tell me about possible problems that i can anticipate.
Best Regards
Yogeeraj

Hello experts,
Once again in seek of guidance..
I am in the process of migrating my database (Oracle 7.2.3 on HP-UX 10.20 to Oracle 8.1.7 64-bits on HP-UX 11).
Amongst one of our steps is to convert our RAW Device datafiles to File System based files within the same server and version - Oracle 7.2.3 on HP-UX 10.20.
E.g. /dev/vg00/rlvol1 to become /d01/oradata/cmtdb/tbs1.dbf
Is this something possible?
Can i just do the following:
a. Shutdown database (normal)
b. dd if=/dev/vg00/rlvol1 of=/d01/oradata/cmtdb/tbs1.dbf bs=20k
c. chown oracle7:dba /d01/oradata/cmtdb/tbs1.dbf
d. svrmgrl> startup mount
e. alter database rename file '/dev/vg00/rlvol1' to '/d01/oradata/cmtdb/tbs1.dbf'
f. alter database open.
Thanks very much for your replies.
Please tell me about possible problems that i can anticipate.
Best Regards
Yogeeraj

Is this a bug in APEX 3.0.1 Installation RAC database with RAW device???

Hello,
I am getting the following error when I try to complete approval process.
ORA-20001: Unable to create tablespace. ORA-01
119: error in creating database file '//./FLOW_1.dbf' ORA-27040: skgfrcre: creat
e error, unable to create file OSD-04002: unable to open file O/S-Error: (OS 2)
The system cannot find the file specified.
I checked the alert log for error here is the error in the alert log file.
ORA-1119 signalled during: CREATE TABLESPACE FLOW_1 DATAFILE '//./FLOW_1.dbf'..
and i found the syntax for create tablespace was wrong.
To create a tablespace in RAC with RAW device environment under windows.
it should have forward black slash instead of backward slash "/" without .dbf extension.
so, I changed the syntax i was able to create tablespace through sqlplus.
When APEX tool try to create this tablespace it throws this error..
Old: CREATE TABLESPACE FLOW_1 DATAFILE
'\\.\FLOW_1.dbf' SIZE 10304 K REUSE AUTOEXTEND OFF
EXTENT MANAGEMENT LOCAL AUTOALLOCATE SEGMENT SPACE MANAGEMENT AUTO
error : ORA-01119: error in creating database file '\\.\FLOW_1.dbf'
New:
CREATE TABLESPACE FLOW_1 DATAFILE
'\\.\FLOW_1' SIZE 10304 K REUSE AUTOEXTEND OFF
EXTENT MANAGEMENT LOCAL AUTOALLOCATE SEGMENT SPACE MANAGEMENT AUTO
Tablespace created.
Is it a bug in APEX 3.0.1.??
Is anyone installed APEX in RAC ??
James

Hi,
One observation, Apex is switching the Session ID after one got killed ? I was working on Apex page with browse Item to test open cursor count,
after killing the SID (227) on which the open cursor count was getting increase, it APEX automatically switches to new SID(149) for that session.
Now the problem is even if I have two SID's and one hits the maximum open cursor count, It is not switching to other SID instead the whole application becomes unavailable.
STATNAME SID VALUE USER
opened cursors current 20 14 APEX_PUBLIC_USER
opened cursors current 149 74 APEX_PUBLIC_USER
opened cursors current 194 71 APEX_PUBLIC_USER
opened cursors current 211 5 APEX_PUBLIC_USER
opened cursors current 227 325 APEX_PUBLIC_USER Killed
opened cursors current 244 15 APEX_PUBLIC_USER
opened cursors current 20 14 APEX_PUBLIC_USER
opened cursors current 149 76 APEX_PUBLIC_USER
opened cursors current 194 71 APEX_PUBLIC_USER
opened cursors current 211 5 APEX_PUBLIC_USER
opened cursors current 244 15 APEX_PUBLIC_USER
Please kindly help in this.
Thanks in Advance
Thanks & Regards
Sanjay
Edited by: user11204334 on Dec 8, 2010 1:02 AM

Database in Raw device recover in time tablespace

How recover database in raw device using clone database
(Recovery Manager) ?
The problem is follow:
When RMAN begin then recover proces he need create the clone
database. @ How create this database ? @ In file system or raw
device ? if he create it in raw device @ Then device necessary
must be created before ?
@ How many devices ? @ What is your size ?
Thanks ...
null

With raw devices alternative cost of performance is typical management difficulties like this, but after 10g ASM is a big shift - http://www.dbazine.com/olc/olc-articles/still5
http://download.oracle.com/docs/cd/B19306_01/server.102/b14231/storeman.htm#i1021337
Best regards.

Advantage of using RAW devices for storing database

Hi,
Marry Christmas to all.
Oracle 10g version 10.2.0.1.0 (rac)
OS : HP-UX 11i
I am new to this enviornment. We are using raw devices for storig the database.
Please tell what are the advantages for using raw devices for storing the database?
Thanks.

http://www.fors.com/orasupp/unix/37914_1.HTM
The above link explains the raw devices and advantages.

Is database using File system, RAW devices or ASM?

Hi there
Is is possible to find out if the database is using File system, RAW devices or ASM for storage?
I think for ASM, we can tell by querying the V$DATAFILE view if it has ' DATA ' or something like that (a name that has ' ' prefixed to it). Is this the only way? How about other sotrage types (RAW and Filesystem)?
Thanks in advance!

user12033597 wrote:
I think for ASM, we can tell by querying the V$DATAFILE view if it has ' DATA ' or something like that (a name that has ' ' prefixed to it). Is this the only way? How about other sotrage types (RAW and Filesystem)?V$DATAFILE or DBA_DATA_FILE
Raw depends on your OS - in *nix, likely something like /dev/sdc1
ASM depends on ASM and will include + and will follow an ASM pattern, such as described http://docs.oracle.com/cd/B19306_01/server.102/b14200/clauses004.htm
File depends on OS - in *nix, likely start with a '/' and NOT be in /dev or /proc. In Winders start with C:\ or some other disk path.
Nicely discussed in the docs in the Administrators Guide found at http://tahiti.oracle.com

Why don't we keep Oracle Database ARCH logs in RAW devices

Hi All,
Why don't we keep Oracle Database ARCH logs in RAW devices?
How ARCH process is related to Block Device and Character Device ?
Thanks,
Tusar
Edited by: user11987718 on 26-Jun-2012 09:59

Why don't we keep Oracle Database ARCH logs in RAW devices? 1.This is because raw devices do not enable sequential writing of consecutive archive log files.
http://docs.oracle.com/cd/E11882_01/rac.112/e16795/rman.htm#RACAD320
2.with raw you have to specify the exact size of the file at creation time, in contrast with file system, where you can create file without specifying its size, start writing to it, apending new blocks to it until you are done, and thus creating a file of whatever size it needs to be to hold all information.
http://www.dbasupport.com/forums/archive/index.php/t-16429.html
3.raw file systems are difficult to manage because you cannot run normal os commands on them.(as there is no file systems)
How ARCH process is related to Block Device and Character Device ?A block device would read/write bytes in fixed size blocks, as in disk sectors. Character devices read/write 0 or more bytes, in a stream, such as a TTY or a keyboard.
For more details about what is block and character device type :
http://en.wikipedia.org/wiki/Device_file
And now think, how arch process is related to block and character devices.
Regards
Girish Sharma

Database Data files on RAW Devices

Hi,
I'm creating a database and wish to locate the tablespaces on a raw device.
How do I specify the datafiles for the tablespaces on the raw device.

> Any reason for moving to raw device?
I actually prefer raw devices and ASM over using cooked file systems.
By default RAW devices eliminate the "interference" of the kernel. It does not manage a file system on the device. There are no other foreign processes that can use that raw device (as is often the case with cooked devices). There is no o/s file system cache for that device. A physical I/O on the Oracle side means a dinkum physical I/O and not a maybe-logical-I/O-from-the-file-system-o/s-cache.
There is no need for me as DBA to manage that file system according to OFA standards (ASM does it for me). There is no need for me to go through the learning curve of using a 3rd party volume manager. I have features like automated load balancing while the instance is up and running.
Yes, there is an argument to be made for just how much of a performance improvement in I/O one can get from a raw device versus a cooked file system. But I/O performance is not the only consideration.

Raw device for oracle 8.1.7 on AIX 4.3.3

Hi there,
I am trying to use a raw device on AIX 4.3.3 for ORACLE 8.1.7.
I have created a raw device /dev/or_system
brw-rw---- 1 oracle dba 54, 1 Mar 04 10:44 or_system
but it is not possible to create a datafile on it :
SVRMGR> create database "GLM"
maxinstances 8
character set "WE8ISO8859P1"
datafile '/dev/or_system' size 150M REUSE
logfile
GROUP 1 ('/oracle/GLM/redo/log1.ora') size 100M,
GROUP 2 ('/oracle/GLM/redo/log2.ora') size 100M,
GROUP 3 ('/oracle/GLM/redo/log3.ora') size 100M,
GROUP 4 ('/oracle/GLM/redo/log4.ora') size 100M;
create database "GLM"
ORA-01501: CREATE DATABASE failed
ORA-01519: error while processing file '?/rdbms/admin/sql.bsq' near line 407
ORA-00604: error occurred at recursive SQL level 1
ORA-01119: error in creating database file '/dev/or_system'
ORA-27038: skgfrcre: file exists
SVRMGR>
The ORA-27028 in exact this situation was reported as a bug in prior ORACLE Versions 8.0.4/ 8.0.5 and had
the bug no. 690228.
But we use as mentioned 8.1.7.
What do I do wrong?
Any suggestions are welcome.
Thank you
Gerhard

Each raw device you create is used as a single data file.
Eg mklv -y 'myfile' <vgname> <number of logical partitians>
Will have two special files associated with them /dev/rmyfile and /dev/myfile. The number of logical partitians will be the size of your datafile subtract 1 meg for overhead.
So, if you were addding the above raw volume to a tablespace, and the lp size was 32 meg, you would
create tabelspace tsname datafile '/dev/rmyfile' size 31 m;
Note the use of rmyfile not myfile.

10g ASM on Logical Volumes vs. Raw devices and SAN Virtualization

We are looking at setting up our standards for Oracle 10g non-rac systems. We are looking at the value of Oracle ASM in our environment.
As per the official Oracle documentation, raw devices are preferred to using Logical Volumes when using ASM.
From here: http://download.oracle.com/docs/cd/B19306_01/server.102/b15658/appa_aix.htm#sthr
ef723
"Note: Do not add logical volumes to Automatic Storage Management disk groups. Automatic Storage Management works best when you add raw disk devices to disk groups. If you are using Automatic Storage Management, then do not use LVM for striping. Automatic Storage Management implements striping and mirroring."
Also, as per Metalink note 452924.1:
"10) Avoid using a Logical Volume Manager (LVM) because an LVM would be redundant."
The issue is: if we use raw disk devices presented to ASM, the disks don't show up as used in the unix/AIX system tools (i.e. smit, lspv, etc.). Hence, when looking for raw devices on the system to add to filesystems/volume groups/etc., it's highly possible that a UNIX admin will grab a raw device that is already in use by Oracle ASM.
Additionally, we are using a an IBM DS8300 SAN with IBM SAN Volume Controller (SVC) in front of it. Hence, we already have storage virtualization and I/O balancing at the SAN/hardware level.
I'm looking for a little clarification to the following questions, as my understanding of their responses seem to confict:
QUESTION #1: Can anyone clarify/provide additional detail as to why Logical volumes are not preferred when using Oracle ASM? Does the argument still hold in a SAN Virtualized environment?
QUESTION #2: Does virtualization at the software level (ASM) make sense in our environment? As we already have I/O balancing provided at the hardware level via our SVC, what do we gain by adding yet another level of I/O balancing at the ASM level? Or as in the
arguments the Oracle documentation makes against using Lvm, is this an unnecessary redundant striping (double-striped or in our case triple-striped/plaid)?
QUESTION #3: So does SAN Virtualization conflict or compliment the virtualization provided by ASM?

After more research/discussions/SR's, I've come to the following conclusion.
Basically, in an intelligent storage environment (i.e. SVC), you're not getting a 100% bang for the buck by using ASM. Which is the cat's meow in a commodity hardware/unintelligent storage environment.
Using ASM in a SVC environment potentially wastes CPU cycles having ASM balance i/o that is already balanced on the backend (sure if you shuffle a deck of cards that are already shuffled you're not doing any harm, but if they're already shuffled - then why are you shuffling them again??).
That being said, there may still be some value for using ASM from the standpoint of storage management for multiple instances on a server. For example, one could better minimize space wastage by being able to share a "pool" of storage between mulitiple instances, rather than having to manage space on an instance-by-instance (or filesystem by filesystem) level.
Also, in the case of having a unfriendly OS where one is unable to dynamically grow a filesystem (i.e. database outage required), there would be a definite benefit provided by ASM in being able to dynamically allocate disks to the "pool". Of course, with most higher-end end systems, dynamic filesystem growth is pretty much a given.
In the case of RAC, regardless of the backend, ASM with raw is a no-brainer.
In the case of a standalone instance, it's a judgement call. My vote in the case of intelligent storage where one could dynamically grow filesystems, would be to keep ASM out of the picture.
Your vote may be different....just make sure you're putting in a solution to a problem and not a solution that's looking for a problem(s).
And there's the whole culture of IT thing as well (i.e. do your storage guys know what you're doing and vice versa).....which can destroy any technological solution, regardless of how great it is.

Content Server 6.40 on Raw Devices

Hi Folks!
We'd like to install a Content Server 6.40 using raw devices (on Linux Suse SLES9).
Do we need to install the MaxDB, if we use raw devices? At this point the InstGuide does not give a clear description of what to do. It looks we can use the raw devices directly without having a database instance. Is this right?
Is there any disadvantage compared to using the access via file system and DB?
Any hint is appreciated...
Best regards
Torsten

Hi Torsten,
As far as i know SAP Content Server use MaxDB or a File System, I have use it with MaxDB with good results, anyhow.... read the following for details,
http://help.sap.com/saphelp_nw04s/helpdata/en/40/32104211625933e10000000a155106/content.htm
Regards
Juan
Please reward with points if helpdul

Using raw device

Good morning,
I would like to make some i/o test with a database version 10g, actually I have the redo log on standard zfs filesystem (cooked), I would like to
migrate this redo log on raw device without recreating the database, is this possible ?
Thanks for your help
Fabrice Chapuis

One more question, in case of node failure , redo on raw device are more critical for a recover than if they were on a filesystem ?More critical? Or more difficult?
Redo is critical, period. Does not matter whether you use a cooked file system or a raw device.
As for difficulty - that depends on what you are attempting to do. If you want to treat the raw device as a file system, that will be difficult as it it not a file system. (which kind of begs the question as to treat it like a file system when it is not?)
From a RMAN perspective - a device is a device. RMAN does not care.
From a DB perspective - that is why ASM exist. To remove the complexities of using raw devices, and eliminate the requirement of needing to use an external Volume Manager. And provide the DBA with a familiar SQL*Plus interface and SQL commands to administer ASM.
It may seem difficult at first - but anything that needs a learning curve to go through, tends to seem difficult in the beginning. All you need to do is learn the basics and grasp the concepts.. and that +"difficulty"+ disappears.

10.1.0.3 on RH4(Centos) + Raw devices + ASM + RAC

Hi,
I'm just wondering if anyone here tried installing a single node RAC on 2 instance using ASM on Oracle 10g (10.1.0.3)?
I am using RH4(CENTOS 4.1), Oracle 10.1.0.3 + CRS 10.1.0.3 on fake raw devices in Linux.
I have been able to install the CRS and Oracle database software successfully.
All CRS services and listener are up and running.
crs_stat command return successful results.
srvctl status nodeapps -n <node_name> also returns successful results.
However, when I attempt to startup the ASM instance, I keep encountering these errors:
ORA-00603:ORACLE server session terminated by fatal error
ORA-27504:IPC error creating OSD context
The ORA-00603 error message will appear immediately in the SQLPLUS prompt when I try to startup ASM instance.
Both errors will be logged in alert.log and trace files, no other useful error messages besides these errors.
When I attempt to create a normal database instance using datafiles on the same machine, these errors also appear again!
So, I figure its got nothing to do with the raw devices since my OCR location and Voting devices are using the same raw devices on Linux.
Anyone did the same thing like me and faced similar problems.... please help.
Cheers

You can use dbca to create ASM instance to get rid of the manual copy business.
In realease 1, you can invoke dbca, choose database instance and walk through still you reach storage clause and choose asm and DBA will create ASM instance on both nodes.
Ensure that you choose cluster install option and all the nodes at the initial stages.

Raw device based database

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