ASMlib driver is required on  Linux operating systems, to enable a disk readable by ASM. Without ASMLIB, disks can-t be used at asm disks.

Below are the steps for configuring ASMlib and marking disks as ASM.

 

  • Download Asmlib:
  • You can download these rpm packages directly from OTN:

    http://www.oracle.com/technetwork/server-storage/linux/downloads/index-088143.html

    Else, if your system is registered with ULN, then you can download directly using yum as below.

    - Run as root on the database server
    
    yum install oracleasm-support oracleasmlib oracleasm-`uname -r` 
    

           2. Configure oracleasm:[ Do on all nodes if RAC]

     

    [root$mapper]#  /etc/init.d/oracleasm configure
    Configuring the Oracle ASM library driver.
    
    This will configure the on-boot properties of the Oracle ASM library
    driver.  The following questions will determine whether the driver is
    loaded on boot and what permissions it will have.  The current values
    will be shown in brackets ('[]').  Hitting  without typing an
    answer will keep that current value.  Ctrl-C will abort.
    
    Default user to own the driver interface []: oracle
    Default group to own the driver interface []: oinstall
    Start Oracle ASM library driver on boot (y/n) [n]: y
    Scan for Oracle ASM disks on boot (y/n) [y]: y
    Writing Oracle ASM library driver configuration: done
    Initializing the Oracle ASMLib driver:                     [  OK  ]
    Scanning the system for Oracle ASMLib disks:               [  OK  ]
    
    

           3. Start oracleasm:[ Do on all nodes ]

    # /etc/init.d/oracleasm start
    Initializing the Oracle ASMLib driver:                     [  OK  ]
    Scanning the system for Oracle ASMLib disks:               [  OK  ]
    

    Now as we have configured and started the oracleasm, we can proceed with making the disks as ASM disk.

        4.Create ASM disk [ Do only from one node ]

    Createdisk need to be run only from one node

    # /etc/init.d/oracleasm createdisk MGMTP1 /dev/mapper/mpathup1
    Marking disk "MGMTP1" as an ASM disk:                      [  OK  ]
    

       5.Now list and scan the disks [ On all the nodes ]

    Once disk is created, you need to scan the disks using scandisks on all the nodes,

    #  /etc/init.d/oracleasm scandisks
    #  /etc/init.d/oracleasm listdisks
    

    Now, these ASM disks are ready to be added to ASM disk group.

    automatic start can be enabled or disabled with the -enable- and -disable- options to /etc/init.d/oracleasm:

          
    -- Enable 
                                         
    # /etc/init.d/oracleasm disable
      Writing Oracle ASM library driver configuration            [  OK  ]
      Unmounting ASMlib driver filesystem                        [  OK  ]
      Unloading module "oracleasm"                               [  OK  ]
    
    -- Disable 
    
    # /etc/init.d/oracleasm enable
      Writing Oracle ASM library driver configuration            [  OK  ]
      Loading module "oracleasm"                                 [  OK  ]
      Mounting ASMlib driver filesystem                          [  OK  ]
      Scanning system for ASM disks                              [  OK  ]
    
    

    Delete asmdisk

    Disks that are no longer used by ASM can be unmarked using deletedisk command

    oracleasm deletedisk

     oracleasm deletedisk OCRVD1
    

    Check whether a disk is already marked for asm or not:

    [root~]# oracleasm querydisk /dev/emcpowerac1
    Device "/dev/emcpowerac1" is marked an ASM disk with the label "REDO1"
    
    

    Get physical disk details with ASM DISK NAMES:

    blkid command will give information about the physical disks and respective asmdisk label name

    [rootmapper]# /sbin/blkid 
    /dev/sdm1: LABEL="REDO06" TYPE="oracleasm"
    /dev/sdp1: LABEL="REDO04" TYPE="oracleasm"
    /dev/sds1: LABEL="REDO03" TYPE="oracleasm"
    /dev/sdv1: LABEL="REDO01" TYPE="oracleasm"
    /dev/sdy1: LABEL="REDO05" TYPE="oracleasm"
    /dev/sdab1: LABEL="REDO02" TYPE="oracleasm"
    /dev/sdjn1: LABEL="REDO04" TYPE="oracleasm"
    /dev/sdjk1: LABEL="REDO06" TYPE="oracleasm"
    /dev/sdjq1: LABEL="REDO03" TYPE="oracleasm"
    /dev/sdjt1: LABEL="REDO01" TYPE="oracleasm"
    /dev/sdjw1: LABEL="REDO05" TYPE="oracleasm"
    /dev/sdjz1: LABEL="REDO02" TYPE="oracleasm"
    /dev/mapper/mpathop1: LABEL="REDO04" TYPE="oracleasm"
    /dev/mapper/mpathup1: LABEL="REDO01" TYPE="oracleasm"
    /dev/mapper/mpathyp1: LABEL="REDO05" TYPE="oracleasm"
    /dev/mapper/mpathsp1: LABEL="REDO03" TYPE="oracleasm"
    /dev/mapper/mpathmp1: LABEL="REDO06" TYPE="oracleasm"
    /dev/mapper/mpathalp1: LABEL="REDO02" TYPE="oracleasm"
    
    
    
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