Adding or Removing Coordinator Disks

This section describes how to destroy or replace a coordinator disk in the coordinator disk group. Adding or removing coordinator disks requires all services be shut down.

Note the following about the procedure:

  A coordinator disk group requires an odd number (three minimum) of disks/LUNs.

  When adding a disk, add the disk to the disk group vxfencoorddg and retest the group for support of SCSI-III persistent group reservations.

  You can destroy the coordinator disk group such that no registration keys remain on the disks. The disks can then be used elsewhere.

  To remove and replace a disk in the coordinator disk group

1. Log in as root user on one of the cluster systems.
2. If VCS is running, shut it down:
     # hastop -all
3. Stop I/O fencing on all nodes:
   # /sbin/init.d/vxfen stop

   This removes any registration keys on the disks.

4. Import the coordinator disk group. The file /etc/vxfendg includes the name of the disk group (typically, vxfencoorddg) that contains the coordinator disks, so use the command:
     # vxdg -tfC import 'cat /etc/vxfendg'

   where:

   -t specifies that the disk group is imported only until the system restarts.

   -f specifies that the import is to be done forcibly, which is necessary if one or more disks is not accessible.

   -C specifies that any import blocks are removed.

5. To remove disks from the disk group, use the VxVM disk administrator utility, vxdiskadm.

   ---

     Note    You may also destroy the existing coordinator disk group. For example:
   # vxdg destroy vxfencoorddg

   ---

6. Add the new disk to the system, initialize it as a VxVM disk, and add it to the vxfencoorddg disk group. Refer to Setting Up the Disk Group for Coordinator Disks
7. Test the recreated disk group for SCSI-III persistent group reservations compliance. Refer to Requirements for Coordinator Disks.
8. After replacing disks in a coordinator disk group, deport the disk group:
     # vxdg deport 'cat /etc/vxfendg'
9. On each node in the cluster, start the I/O fencing driver:
     # /sbin/init.d/vxfen start
10. Restart VCS. On each node, enter:
      # hastart