Replacing nodes disruptively (moving VDisks to new I/O group)

You can replace SAN Volume Controller 2145-8F2, SAN Volume Controller 2145-8F4, or SAN Volume Controller 2145-8A4 nodes with SAN Volume Controller 2145-8A4 or SAN Volume Controller 2145-CF8 nodes. The following procedures are disruptive, because you move VDisks to a new I/O group.

This task assumes the following:
  • The cluster software is at 5.1.0 or higher
  • Your cluster contains six or less nodes
  • All nodes that are configured in the cluster are present
  • All errors in the cluster error log are fixed
  • All managed disks (MDisks) are online
  • You have a 2145 UPS-1U unit for each new SAN Volume Controller 2145-8G4 node.

Perform the following steps to replace nodes:

  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 groups of the nodes that you are replacing.
  3. Add two replacement nodes to the cluster to create a new I/O group.
  4. Rezone your switch zones to add the ports of the new nodes to the host and storage zones.
  5. Move all of the VDisks from the I/O group of the nodes that you are replacing to the new I/O group.
  6. From each host, issue a rescan of the multipathing software to discover the new paths to VDisks. The host multipathing device drivers take approximately 30 minutes to recover the paths.
  7. 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.
  8. Delete the nodes that you are replacing from the cluster and remove the ports from the switch zones.
  9. Repeat steps 2 to 8 for each node in the cluster that you want to replace.
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