10 Replies Latest reply: Dec 13, 2012 3:52 AM by Gennady Sigalaev RSS

    udev rules list for 10.2 RAC

    spiral
      CRS version: 10.2.0.5
      Platform : RHEL 5.4

      I come from the land of Solaris where there is no need of scary utilities like oracleasm. Now, we want to move one of our 10.2 clusters to RHEL 5.4.

      Is it possible to create ASM LUNs without oracleasm (ASMLib ) in 10.2 CRS/ASM ?

      From which version of Oracle were we able to configure ASM LUNs without oracleasm and just use udev rules list ?
        • 1. Re: udev rules list for 10.2 RAC
          Gennady Sigalaev
          Hi spiral,
          Is it possible to create ASM LUNs without oracleasm (ASMLib ) in 10.2 CRS/ASM ?
          Yes, it is possible.
          From which version of Oracle were we able to configure ASM LUNs without oracleasm and just use udev rules list?
          Oracle RAC was introduced in 9i version, so probably since that time. But in old linux you should configure raw files. in RHEL 5 you can use udev for it.
          I've installed RAC 11gR1 and 11GR2 using udev and didn't have any problems.

          Best regards,
          Gennady
          • 2. Re: udev rules list for 10.2 RAC
            LaserSoft
            Hi Spiral

            Good Question.

            Oracle recommends using ASM with ASMLib together for better manageability and persistent device naming.

            Oracle introduced ASMLib in 2004 to provide Oracle workloads on Linux with performance and stability comparable to equivalent workloads on UNIX.

            Yes. It is possible to run an Oracle Single Instance database with ASM and without ASMLib by specifying udev rules and/or using device mapper multipathing to achieve persistent device naming


            ASM can use the following for storage resources:

            *• Block devices (SATA, SAS, FC, iSCSI, FCoE, regular LUNs and LUNs with thin provisioning) with udev naming and/or multipathing.*
            *• Raw Devices.*
            *• NFS v3 with verified NAS vendors.*

            Thanks
            LaserSoft
            • 3. Re: udev rules list for 10.2 RAC
              Levi Pereira
              From which version of Oracle were we able to configure ASM LUNs without oracleasm and just use udev rules list ?
              All version. ASMLib never was mandatory.

              I suggest the documentation 11.2 which is more complete and is also valid to 10.2

              3.3.1.6 Configuring Disk Devices Manually for Oracle ASM
              http://docs.oracle.com/cd/E11882_01/install.112/e22489/storage.htm#CDECEBGH

              Block devices are supported with the Oracle Database 10.2.0.2 and higher.

              I still prefer to use ASMLib under Linux env:

              Nice article about ASMLib:
              https://blogs.oracle.com/wim/entry/asmlib

              Advantages for using ASMLib :
              * A good async IO interface for the database, the entire IO interface is based on an optimal ASYNC model for performance
              * A single file descriptor per Oracle process, not one per device or datafile per process reducing # of open filehandles overhead
              * Device scanning and labeling built-in so you do not have to worry about messing with udev or devlabel, permissions or the likes which can be very complex and error prone.


              Q: Why not use Grid Infrastructure 11.2? Since GI support Oracle RAC (10.1/10.2/11.1/11.2)

              I see no advantage to install CRS 10.2.
              In my view use Oracle Database 10.2 is acceptable due application compatibility, but about clusterware version, I think GI 11.2 is the best option because it have all feature of previous version and is fully supported to all RAC Version
              • 4. Re: udev rules list for 10.2 RAC
                Gennady Sigalaev
                Hi Levi,
                Block devices are supported with the Oracle Database 10.2.0.2 and higher.
                From your link
                With the release of Oracle Database 11g release 2 (11.2) and Oracle RAC 11g release 2 (11.2), using Database Configuration Assistant or the installer to store Oracle Clusterware or Oracle Database files on block or raw devices is not supported.
                Best regards,
                Gennady
                • 5. Re: udev rules list for 10.2 RAC
                  Levi Pereira
                  Gennady Sigalaev wrote:
                  Hi Levi,
                  Block devices are supported with the Oracle Database 10.2.0.2 and higher.
                  From your link
                  With the release of Oracle Database 11g release 2 (11.2) and Oracle RAC 11g release 2 (11.2), using Database Configuration Assistant or the installer to store Oracle Clusterware or Oracle Database files on block or raw devices is not supported.
                  OP:
                  CRS version: 10.2.0.5
                  Platform : RHEL 5.4
                  I just suggested the configuration of UDEV of docs 11.2 that is more complete.

                  Although the documentation is for version 11.2, this exclusive part of the documentation can be used to perform settings of devices that will be used in version 10.2/11.1/11.2
                  I suggest the documentation 11.2 which is more complete and is also valid to 10.2
                  3.3.1.6 Configuring Disk Devices Manually for Oracle ASM
                  http://docs.oracle.com/cd/E11882_01/install.112/e22489/storage.htm#CDECEBGH
                  By default, the 2.6 kernel device file naming scheme udev dynamically creates device file names when the server is started, and assigns ownership of them to root. If udev applies default settings, then it changes device file names and owners for voting disks or Oracle Cluster Registry partitions, corrupting them when the server is restarted. For example, a voting disk on a device named /dev/sdd owned by the user grid may be on a device named /dev/sdf owned by root after restarting the server.If you use ASMLIB, then you do not need to ensure permissions and device path persistency in udev.

                  This above apply to CRS 10.2 too.
                  • 6. Re: udev rules list for 10.2 RAC
                    spiral
                    I still prefer to use ASMLib under Linux env:

                    Would you suggest ASMLib for 11.2 Grid in RHEL 5.4 or Oracle Enterprise Linux 6 (UEK) environment ?
                    • 7. Re: udev rules list for 10.2 RAC
                      Levi Pereira
                      Since you will need to Install Oracle Database 10.2.0.5 you should use RHEL or OEL 5. "Red Hat Enterprise 5 (10.2.0.3 or later for RAC)"

                      Reason: Oracle Database 10.2.0.5.0 is not certified on Linux x86-64 OEL/RHEL 6.

                      It's fine to setup GI/ASM 11.2 with ASMLib.

                      Regards,
                      Levi Pereira.
                      • 8. Re: udev rules list for 10.2 RAC
                        Gennady Sigalaev
                        I am not Levi, but if you don't mind I answer. Oracle recommends using ASMLib for OEL, so I think you should follow this recommendation.
                        • 9. Re: udev rules list for 10.2 RAC
                          Levi Pereira
                          I misunderstood your reply. My apologies.

                          I have the same thought, we should implement ASMLib in Linux environment. I don't discard this option unless have a reason to not do it.

                          Edited by: Levi Pereira on Dec 12, 2012 4:16 PM

                          Edited by: Levi Pereira on Dec 12, 2012 4:44 PM
                          • 10. Re: udev rules list for 10.2 RAC
                            Gennady Sigalaev
                            Hi Levi,

                            The topic starter asked - Is it possible to create ASM LUNs without oracleasm (ASMLib ) in 10.2 CRS/ASM ?
                            I answer that it possible. When I used udev instead of ASMLib I had a reason for that. The reason was the impossibility to change the ASMlib after update OS (OEL), currently ASMlib has command "update-driver", details here (http://www.pythian.com/news/18977/updating-asmlib-driver-using-update-driver), so since Oracle introduced this feature I have installed a lot of RAC configurations using ASMLib and have not had any problems.

                            Basically, I always follow Oracle's recommendations.

                            I hope it explains my thoughts.

                            Best regards,
                            Gena