Replacing nodes disruptively (rezoning the SAN)

You can replace SAN Volume Controller 2145-8F2, SAN Volume Controller 2145-8F4, SAN Volume Controller 2145-8A4, or SAN Volume Controller 2145-8G4 nodes with SAN Volume Controller 2145-8A4 or SAN Volume Controller 2145-CF8 nodes. The following procedures are disruptive, because you do not use the same WWNN and WWPNs for the new node. You must rezone your SAN and the host multipathing device drivers must discover new paths. Access to virtual disks (VDisks) is lost during this task.

1. (If the cluster software version is at 5.1, complete this step.)

   Confirm that no hosts have dependencies on the node.

   When shutting down a node that is part of a cluster, or when deleting the node from a cluster, use the Show Dependent VDisks menu option on the Viewing Nodes panel in the SAN Volume Controller Console to display all the VDisks that are dependent on a node, or use the svcinfo lsnodedependentvdisk command to view dependent VDisks.

   If dependent VDisks exist, determine if the VDisks are being used. If the VDisks are being used, either restore the redundant configuration or suspend the host application. If a dependent quorum disk is reported, repair the access to the quorum disk or modify the quorum disk configuration.

2. Quiesce all I/O from the hosts that access the I/O group of the node that you are replacing.
3. Delete the node that you want to replace from the cluster and I/O group.
   Notes:

   1. The node is not deleted until the SAN Volume Controller cache is destaged to disk. During this time, the partner node in the I/O group transitions to write through mode.
   2. You can use the command-line interface (CLI) or the SAN Volume Controller Console to verify that the deletion process has completed.
4. Ensure that the node is no longer a member of the cluster.
5. Power-off the node and remove it from the rack.
6. Install the replacement (new) node in the rack and connect the uninterruptible power supply cables and the fibre-channel cables.
7. Power-on the node.
8. Rezone your switch zones to remove the ports of the node that you are replacing from the host and storage zones. Replace these ports with the ports of the replacement node.
9. Add the replacement node to the cluster and I/O group.
   Important: Both nodes in the I/O group cache data; however, the cache sizes are asymmetric if the remaining partner node in the I/O group is a SAN Volume Controller 2145-4F2 node. The replacement node is limited by the cache size of the partner node in the I/O group. Therefore, the replacement node does not use the full 8 GB cache size until you replace the other SAN Volume Controller 2145-4F2 node in the I/O group.
10. From each host, issue a rescan of the multipathing software to discover the new paths to VDisks.
    Notes:

    1. If your system is inactive, you can perform this step after you have replaced all nodes in the cluster.
    2. The host multipathing device drivers take approximately 30 minutes to recover the paths.
11. See the documentation that is provided with your multipathing device driver for information on how to query paths to ensure that all paths have been recovered before proceeding to the next step.
12. Repeat steps 2 to 11 for the partner node in the I/O group.
13. Repeat steps 2 to 12 for each node in the cluster that you want to replace.
14. Resume host I/O.