Configuring Disks for ASM

Configuring Disks for ASM

To configure disks for use with ASM on AIX, follow these steps:

    If necessary, install the shared disks that you intend to use for the ASM disk group and restart the system.

    To make sure that the disks are available, enter the following command on every node:

    # /usr/sbin/lsdev -Cc disk


    The output from this command is similar to the following:

    hdisk0 Available 1A-09-00-8,0  16 Bit LVD SCSI Disk Drive
    hdisk1 Available 1A-09-00-9,0  16 Bit LVD SCSI Disk Drive
    hdisk2 Available 17-08-L       SSA Logical Disk Drive


    If a disk is not listed as available on any node, enter the following command to configure the new disks:

    # /usr/sbin/cfgmgr


    Enter the following command on any node to identify the device names for the physical disks that you want to use:

    # /usr/sbin/lspv | grep -i none


    This command displays information similar to the following for each disk that is not configured in a volume group:

    hdisk2     0000078752249812   None


    In this example, hdisk2 is the device name of the disk and 0000078752249812 is the physical volume ID (PVID). The disks that you want to use might have a PVID, but they must not belong to a volume group.

    If a disk that you want to use for the disk group does not have a PVID, enter a command similar to the following to assign one to it:

    # /usr/sbin/chdev -l hdiskn -a pv=yes


    On each of the other nodes, enter a command similar to the following to identify the device name associated with each PVID on that node:

    # /usr/sbin/lspv | grep -i 0000078752249812


    Depending on how each node is configured, the device names might differ between nodes.

    To enable simultaneous access to a disk device from multiple nodes, you must set the appropriate Object Data Manager (ODM) attribute listed in the following table to the value shown, depending on the disk type:
    Disk Type     Attribute     Value
    SSA or FAStT disks     reserve_lock     no
    ESS, EMC, HDS, CLARiiON, or MPIO-capable disks     reserve_policy     no_reserve

    To determine whether the attribute has the correct value, enter a command similar to the following on all cluster nodes for each disk device that you want to use:

    # /usr/sbin/lsattr -E -l hdiskn

    If the required attribute is not set to the correct value on any node, enter a command similar to one of the following on that node:

        SSA and FAStT devices:

        # /usr/sbin/chdev -l hdiskn  -a reserve_lock=no


        ESS, EMC, HDS, CLARiiON, and MPIO-capable devices:

        # /usr/sbin/chdev -l hdiskn  -a reserve_policy=no_reserve


    Enter commands similar to the following on any node to clear the PVID from each disk device that you want to use:

    # /usr/sbin/chdev -l hdiskn -a pv=clear


    Enter commands similar to the following on every node to change the owner, group, and permissions on the character raw device file for each disk that you want to add to the disk group:

    # chown oracle:dba /dev/rhdiskn
    # chmod 660 /dev/rhdiskn


    Note:
    If you are using a multi-pathing disk driver with ASM, make sure that you set the permissions only on the correct logical device name for the disk.

    The device name associated with a disk might be different on other nodes. Make sure that you specify the correct device name on each node.

    If you also want to use raw devices for storage, refer to the "Configure Raw Devices" section.

    Otherwise, refer to the "Verify the Cluster Software Configuration" section.