Upgrading

To upgrade to a newer version of IBM Spectrum Scale, first consider the version that you are upgrading from and then consider coexistence and compatibility issues.

IBM Spectrum Scale supports a limited form of backward compatibility between two adjacent releases. Limited backward compatibility allows you to temporarily operate with a mixture of IBM Spectrum Scale nodes running on the newer version and nodes running an earlier version:
  • Within a cluster this enables you to perform an online upgrade to the new IBM Spectrum Scale version of the code provided upgrade from your current version to the newer version is supported.
  • In a multicluster environment this allows the individual clusters to be upgraded on their own schedules. Access to the file system data can be preserved even though some of the clusters might still be running at an earlier version.
  • In multicluster environments, it is recommended to upgrade the accessing clusters before the owning cluster especially if file audit logging, watch folder, clustered watch, and AFM functions are being used.
Note: Nodes with Cluster Export Services (CES) do not allow backwards compatibility. All CES nodes must be at the same version prior to returning client access.

Online upgrades allow you to install new IBM Spectrum Scale code one node at a time while maintaining access to the file systems without shutting down IBM Spectrum Scale on other nodes. However, you must upgrade all nodes within a short time. The time dependency exists because some IBM Spectrum Scale features in the newer version become available on each node as soon as the node is upgraded, while other features will not become available until you upgrade all participating nodes.

You can also perform offline upgrades, if you can shut down the entire cluster. An offline upgrade is similar to the online upgrade procedure. However, due to the entire cluster being offline, it is possible to jump straight to the latest code level instead of hopping to an intermediate level, as might be required during an online upgrade. For information about an offline upgrade procedure, see Offline upgrade with complete cluster shutdown.
Important: Online upgrade from an unsupported version of IBM Spectrum Scale or GPFS is not supported.

For information about the upgrade process flow used by the installation toolkit, see Upgrade process flow. You can use this process flow as a reference for doing manual upgrades on Linux® nodes.

After all nodes are upgraded to the new code, you must finalize the upgrade by running the commands mmchconfig release=LATEST and mmchfs -V full (or mmchfs -V compat). Also, certain new features might require you to run the mmmigratefs command to enable them. For more information, see Completing the upgrade to a new level of IBM Spectrum Scale.

For the latest information on upgrade, coexistence, and compatibility, see the IBM Spectrum Scale FAQ in IBM® Knowledge Center (www.ibm.com/support/knowledgecenter/STXKQY/gpfsclustersfaq.html).

IBM Spectrum Scale upgrade consists of these topics: