Confirming that the logical volume is in a multi-path configuration

Perform the following procedure to confirm that the logical volume is in a multi-path configuration.

1. Use the dmsetup deps -o blkdevname command to check the mapping information of the volume group.

   Depending on the version of the command, the command will return either the device name or the major and minor numbers of the device file.

   If the command returns the device name, go to step 3.

   In the following example, the command returns the device name:

   # dmsetup deps -o blkdevname
   volume group name-logical volume name: N dependencies : (device name)

   In the following example, the command returns the major and minor numbers of the device file:

   # dmsetup deps -o blkdevname
   volume group name-logical volume name: N dependencies : (major number, minor number)

   Check the device name or the major and minor numbers referenced by each logical volume. You can ignore the value of N, which indicates the number of disks that make up the logical volume, because the value is not necessary for this confirmation procedure

2. Check whether the /proc/partitions information contains the name of the device corresponding to the major and minor numbers you checked in step 1.

   The following is an example of executing the command:

   # cat /proc/partitions
   major           minor           #blocks                   name
   major number    minor number   number of logical disk blocks    device name

3. Execute the HDLM-configuration definition utility (dlmcfgmgr) with the -v parameter specified to check the names of the HDLM device and the managed SCSI devices.

   The following is an example of executing the command:

   # /sbin/dlmcfgmgr -v
   HDevName        Management      Device     Host    Channel Target  Lun
   /dev/sddlmaa    configured      /dev/sda         2       0       0       0
                                   /dev/sdh         3       0       0       0
   ...
   KAPL10302-I /sbin/dlmcfgmgr completed normally.

   In this example, the HDLM device name is sddlmaa, and the names of the managed SCSI devices are sda and sdh.

4. Check whether the device name you checked in step 1 or 2 appears in the list of managed SCSI devices. Ignore partition numbers when comparing device names.

   If the device name appears, the corresponding logical volume (volume group) is not in a multi-path configuration.

   If the device name does not appear, the corresponding logical volume (volume group) is in a multi-path configuration.