Upgrading the SAN Volume Controller software

The SAN Volume Controller software can be upgraded while you run day-to-day operations.

However, performance is degraded during the software upgrade process. Only the following commands can be issued during the software upgrade:

All svcinfo commands
svctask rmnode

Attention:

You must upgrade the SAN Volume Controller Console before you upgrade the SAN Volume Controller software.
Applying a software upgrade takes a varying length of time. Plan for at least one hour because there is a 30-minute delay that allows the multipathing software to recover.

Software and microcode for the SAN Volume Controller and its attached adapters is tested and released as a single package. The package number increases each time a new release is made. The package includes Linux®, Apache and the SAN Volume Controller software.

Some software levels support upgrades only from specific previous levels, or the software can be installed only on certain hardware types. If you upgrade to more than one level above your current level, you might be required to install an intermediate level. For example, if you are upgrading from level 1 to level 3, you might have to install level 2 before you can install level 3. For information about the prerequisites for each software level, see the Support for SAN Volume Controller (2145) Web site:

www.ibm.com/storage/support/2145

Attention:

If you apply the software upgrade while a node is in service mode, the node is deleted from the cluster. All status information that is stored on the node is deleted and data loss can occur if the cluster depends solely on this node.
Ensure that you have no unfixed errors in the log and that the cluster date and time are correctly set. Start the Directed Maintenance Procedures (DMPs) and ensure that you fix any outstanding errors before you attempt to concurrently upgrade the software.

Metro Mirror and Global Mirror relationships

When you upgrade software where the cluster participates in one or more intercluster relationships, update the clusters one at a time. Do not upgrade the clusters concurrently because you can lose synchronization and availability.

You can create new Metro Mirror or Global Mirror partnerships between clusters with different software levels. If the partnerships are between a SAN Volume Controller version 5.1.0 cluster and a cluster that is earlier than version 5.1.0, each cluster can participate in a single partnership with another cluster. If the clusters are all SAN Volume Controller version 5.1.0, each cluster can participate in up to four cluster partnerships.

Attention: If you want to upgrade a cluster to SAN Volume Controller version 5.1.0 and the partner is running version 4.2.0 or earlier, you must first upgrade the partner cluster to SAN Volume Controller 4.2.1 or later before you upgrade the first cluster to version 5.1.0.