6.4.2 Determining the values to be specified in the operands required for SCSI reservation of the shared disk if LVM is used

(a) If HFC-PCM is used with a single-path configuration in a VMware ESXi-based virtualization environment

Specify in the scsi_device operand the symbolic link for the shared disk. You can obtain the symbolic link from the path name for the shared disk that is obtained on the basis of the LVM's physical volume name.

To obtain the scsi_device operand value:

1. Check the physical volume name.

   The checking method is as follows:

   #/sbin/vgdisplay -v volume-group-name

   The following example specifies vg01 for the volume group name.

   Example:

   #/sbin/vgdisplay -v vg01

   Execution results:

    --- Volume group ---
    VG Name               vg01
   ...
   ...
    --- Physical volumes ---
    PV Name               /dev/sda1
   ...
   ...
   (omitted)

   The underlined portion is the physical volume name. The numeric digit at the end is the partition number.

2. Obtain the symbolic link.

   Use the command below to obtain the symbolic link that is located under /dev/disk/by-id and that is created by the OS. For the physical volume name, specify the physical volume name checked in step 1 without /dev/ or the partition number.

   # ls -l /dev/disk/by-id | grep physical-volume-name$

   The following example specifies sda for the physical volume name.

   Example:

   # ls -l /dev/disk/by-id | grep sda$

   Execution results:

   lrwxrwxrwx 1 root  9 Jun  7 17:08
   scsi-360060e8010462fe004f2b6ae00000065 -> ../../sda

   The underlined portion is a symbolic link. In the scsi_device operand, specify an absolute path.

   Notes

   Do not specify the following symbolic links for the scsi_device operand:

   • A symbolic link that ends with part

   • A symbolic link that begins with wwn-

(b) Redundant configuration using multipath software (HDLM)

If you use HDLM to make the shared disk path redundant, specify the absolute path of the HDLM's logical device in the scsi_device operand. You can obtain the absolute path from the LVM's physical volume name, which is the same as the HDLM's logical device name with a partition number added.

Execute the following command to check the physical volume name:

#/sbin/vgdisplay -v volume-group-name

The following shows an example that specifies vg01 for volume group.

Example:

#/sbin/vgdisplay -v vg01

Execution results:

 --- Volume group ---
 VG Name               vg01
.
.
 --- Physical volumes ---
 PV Name               /dev/sddlmaa1
.
.
(omitted)

The underlined portion is the LVM's physical volume name. The partition number would be p1 at the end. Specify in the scsi_device operand the LVM's physical volume name without the partition number.

Important

HDLM's logical device name might not be the same among all hosts. Perform this procedure on all hosts in the hot-standby configuration and check the scsi_device operand value.