11 Replies Latest reply: Aug 6, 2012 3:23 AM by Sebastian Solbach -Dba Community-Oracle RSS

    oracleasmlib and oracleasm

    scottjhn
      In order to prepare the ASM disk, I need to install the oracleasmlib package. My understanding of its usage is that this package is SOLEY used for stamping the disk for ASM. After the disk is stamped as an ASM disk, the oracleasmlib is no longer used. The ASM installed via the Grid Infrastructure will manage the disk. Is my understanding correct?
        • 1. Re: oracleasmlib and oracleasm
          Sebastian Solbach -Dba Community-Oracle
          Hi,

          no. ASMLIB will SCAN for the disks and set the device permissions of the stamped disk every time the server is started.
          Furthermore ASMLIB will be the process having the file handles open to the disks. If you don't have asmlib each DB process doing I/O has the file handles.

          Regards
          Sebastian
          • 2. Re: oracleasmlib and oracleasm
            scottjhn
            The reason I asked this question is that without installation of the oraclasm, the SUSE Linux 11 start/reboot smoothly. Now, after install oracleasm, I encountered the following weird situation:

            When I issues oracleasm exit command,

            A black screen appears and displays a long list of info. At its final pause, displays:

            Saving dump using makedumpfile
            Copying data: [1%] It keeps change to --> 2% --> ... 100%.

            When it reaches the 100%, the system reboot.

            Now, , I try to reboot/shutdown the OS. The same thing happens, that is,

            A black screen appears and displays a long list of info. At its final pause, displays:

            Saving dump using makedumpfile
            Copying data: [1%] It keeps change to --> 2% --> ... 100%.

            When it reaches the 100%, the system reboot.

            Now, I remove the installed oracleasmLib, everything returns to normal, I can reboot and shutdown as usual.

            This happens only after I installed the oracleasmLib. At this point, I can not shutdown the machine, because the above described cycle just keep going.

            What could be wrong? How could I fix it? And, how could the oracleasm interferes with the OS?

            Software: Oracle 11gR2 oracleasmLib SUSE Linux Server 11.
            • 3. Re: oracleasmlib and oracleasm
              Sebastian Solbach -Dba Community-Oracle
              Hi,

              sounds like you did not get the correct oracleasm version/kernel version.

              ASMLib is maintained by the Linux vendors, so you should contact SUSE support for help.

              However you don't need ASMLIB. You simply can install RAC and use UDEV/multipath to set the correct device permissions.
              So if you still having problems (even after contacting SUSE support) I would opt for doing this without asmlib (even though I did 2 successfull installations on SLES 11).

              Regards
              Sebastian
              • 4. Re: oracleasmlib and oracleasm
                scottjhn
                Given my situation, can I do this: install the oracleasmlib for preparing (stamping) the disk for ASM usage. After the disk gets stamped, remove the oracleasmLib and let the ASM take care of the rest.

                I know you mentioned:"ASMLIB will SCAN for the disks and set the device permissions of the stamped disk every time the server is started. Furthermore ASMLIB will be the process having the file handles open to the disks. If you don't have asmlib each DB process doing I/O has the file handles."

                So, I am not sure my proposal is feasible? Or have other options?

                (I installed it on a standalone machine)
                • 5. Re: oracleasmlib and oracleasm
                  Sebastian Solbach -Dba Community-Oracle
                  No you can't.

                  Deinstall asmlib and configure your devices with UDEV is you option.

                  Regards
                  Sebastian
                  • 7. Re: oracleasmlib and oracleasm
                    scottjhn
                    See if I understand the issue correctly:

                    Everytime use ASM, the oracleasmlib must be loaded by issuuing: oracleasm init. In this way, I do not need to use the UDEV. Is this correct?


                    Now, after stamping the disk with oracleasmLib, if I de-install the oracleasmLib. In order to make the ASM work, I'll need to configure the disk by UDEV. Is this correct? If so, where can I get the UDEV?
                    • 8. Re: oracleasmlib and oracleasm
                      Sebastian Solbach -Dba Community-Oracle
                      => No you can tell asmlib to load at startup time (with oracleasm configure).
                      => UDEV is part of every Linux installation.

                      PS: RTFM

                      http://docs.oracle.com/cd/E11882_01/install.112/e22489/toc.htm
                      Especially: http://docs.oracle.com/cd/E11882_01/install.112/e22489/storage.htm#CDEBFDEH

                      Sebastian
                      • 9. Re: oracleasmlib and oracleasm
                        onedbguru
                        ASMLib is being EOL'ed... Don't use it. you don't need it. Using it may cause you a LOT of pain in the future. I have NEVER used it as it is wholly unnecessary. Again, RTFineM!!!!!!!
                        • 10. Re: oracleasmlib and oracleasm
                          scottjhn
                          >
                          ASMLib is being EOL'ed... Don't use it. you don't need it. Using it may cause you a LOT of pain in the future. I have NEVER used it as it is wholly unnecessary. Again, RTFineM!!!!!!!
                          >


                          But I do need* the ASMLib to stamp the disk, correct? (For instance, "createdisk DISK1 /dev/sdb".) I asked so, because in the process of installing the Grid Infrastructure/ASM, it asks for the disk group name and the candidate disks, along with redundancy, etc.

                          I would also like to know for a standalone server with local devices only, should I use ASMLib or UDEV?
                          • 11. Re: oracleasmlib and oracleasm
                            Sebastian Solbach -Dba Community-Oracle
                            Hi,

                            I don't agree on ASMLib being EOL'ed (at least not for Oracle Linux and SLES).

                            However onedbguru is totally right in the aspect of you don't need ASMLib for using ASM.

                            So again:

                            You don't need ASMLib to stamp the disks. You can prepare (or stamp if you would like to call it that way) the disks with UDEV / device mapper or even (though not recommended) by a startup script during system boot. Yes you need ASMLib if you would like to work with the default discovery string of 'ORCL:', but simply change it to '/dev/sd*' and you will see all disks belonging to gi user and asmadmin group.

                            Sebastian