Performing a disruptive software upgrade using the CLI

You can use the command-line interface (CLI) to perform a disruptive software upgrade.

The SAN Volume Controller only supports concurrent software upgrades. To ensure that a software upgrade is coordinated across all nodes in the cluster, the nodes must be able to communicate with each other across the fibre-channel SAN. However, if this is not possible, you can perform a disruptive software upgrade.

Perform the following steps to complete the disruptive software upgrade process:

Stop any host applications and unmount the file systems that use storage that is managed by the SAN Volume Controller. If you are shutting down your hosts, this occurs as the host is shutdown. If you are not shutting down your hosts, you must manually stop host applications and unmount the file systems on each host. This step ensures that the hosts stop issuing I/O operations and that any data in the file system caches is flushed.
Issue the svctask stopcluster CLI command to shutdown the cluster. This CLI command stops the SAN Volume Controller from issuing I/O to backend controllers and flushes data from the SAN Volume Controller nodes cache.
Rezone the switch so that the SAN Volume Controller nodes are in one zone. Ensure that this zone does not include a host HBA or a backend controller (keep the old switch configuration so it can be restored during step 6). This step isolates the SAN Volume Controller from the rest of the SAN.
Power on all the SAN Volume Controller nodes and wait for them to reform a cluster.
Note: Because the SAN Volume Controller has been isolated from the backend storage, errors that indicate the backend storage is unavailable are logged.
Perform the software upgrade in the same manner as for a concurrent software upgrade.
Restore the original switch configuration.
Clear any error logs that were produced in step 4 indicating that backend storage is unavailable. Check that all backend storage is now online and accessible to the SAN Volume Controller nodes.
Remount file systems and start host applications.