Migration, coexistence and compatibility
To migrate to a newer version of IBM Spectrum Scale™, first consider the version that you are migrating 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 a rolling upgrade to the new IBM Spectrum Scale version of the code provided migration 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.
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.
Rolling upgrades allow you to install new IBM Spectrum Scale code one node at a time 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. Once all nodes have been migrated to the new code, you must finalize the migration by running the commands mmchconfig release=LATEST and mmchfs -V full (or mmchfs -V compat). Also, certain new features may require you to run the mmmigratefs command to enable them.
Attention: A full backup (-t full)
with mmbackup is required if a full backup
has never been performed with GPFS™ 3.3
or later. For more information, see File systems backed up using GPFS 3.2 or earlier versions of mmbackup.
For the latest information on migration, coexistence, and compatibility, see the IBM Spectrum Scale FAQ in IBM® Knowledge Center.
IBM Spectrum Scale migration consists of these topics:
- Migrating to IBM Spectrum Scale 4.2.y from IBM Spectrum Scale 4.1.x
IBM Spectrum Scale 4.2.y release supports node-at-a-time migration if the previous nodes in the cluster are running IBM Spectrum Scale 4.1.x release. IBM Spectrum Scale 4.1.x nodes can coexist and interoperate with nodes that are running IBM Spectrum Scale 4.2.y, except for object, SMB, and performance monitoring. However, new functions that depend on format changes will not be available until all nodes have been migrated. The following procedure can also be used to migrate from IBM Spectrum Scale 4.2.y to 4.2.z. - Migrating to IBM Spectrum Scale 4.1.1.x from GPFS V4.1.0.x
Use the following information to migrate from V4.1.0.x to V4.1.1.x. - Migrating to IBM Spectrum Scale V4.2 from GPFS V3.5
Node-at-a-time migration is not available when you migrate a cluster to IBM Spectrum Scale V4.2 from GPFS V3.5. You must shut down the cluster and migrate all the nodes at once. If this method is not acceptable, you might consider migrating in two steps: first migrate the cluster from GPFS V3.5 to GPFS V4.1, and then migrate from GPFS V4.1 to IBM Spectrum Scale 4.2. - Migrating to IBM Spectrum Scale 4.2 from GPFS 3.4 or GPFS 3.3
Node-at-a-time migration is not available when migrating to IBM Spectrum Scale 4.2 from GPFS 3.4 or GPFS 3.3. The cluster must be completely shut down and all nodes migrated at the same time. If this is not acceptable, and your current level is GPFS 3.4, you may want to consider an intermediate migration to GPFS 3.5 first. - Upgrading Object packages
Use these steps to upgrade IBM Spectrum Scale for object storage packages. - Upgrading NFS packages
Use these steps on each protocol node one by one to upgrade IBM Spectrum Scale NFS packages. - Upgrading SMB packages
Use these steps to upgrade IBM Spectrum Scale SMB packages. - Manually upgrading pmswift
To upgrade pmswift you can either uninstall and reinstall the pmswift rpm or use the native rpm upgrade command: rpm -Uvh pmswift-version-release.noarch.rpm. After upgrading, restart the service using the following command: systemctl restart pmswiftd.service. - Manually upgrading the Performance Monitoring tool
You can upgrade by uninstalling and then reinstalling the new version of the tool. - Manually upgrading the IBM Spectrum Scale management GUI
You can upgrade the IBM Spectrum Scale management GUI to the latest version to get the latest features. You can upgrade one GUI node at a time without shutting down IBM Spectrum Scale on other nodes to ensure high availability. - Upgrading IBM Spectrum Scale components with the installation toolkit
You can use the installation toolkit to upgrade base GPFS, NFS, Object, SMB, management GUI, and performance monitoring from the current version of IBM Spectrum Scale to the next higher version. For example, you can use the installation toolkit to upgrade from IBM Spectrum Scale release 4.2.1 to release 4.2.2. 
Migrating from Express Edition to Standard Edition
Starting with release 4.2.3, IBM Spectrum Scale Express Edition is no longer available. Use this information for migrating from IBM Spectrum Scale Express Edition 4.2.2.x or earlier to IBM Spectrum Scale Standard Edition 4.2.3.x.- Migrating to Transparent cloud tiering 1.1.2 from Transparent cloud tiering 1.1.0 or 1.1.1
This topic describes the procedure for upgrading to Transparent cloud tiering 1.1.2 from Transparent cloud tiering 1.1.0 or 1.1.1. - Migrating to Cloud services 1.1.2.1 from 1.1.2
This topic describes the procedure for upgrading to Cloud services 1.1.2.1 from 1.1.2. - Migrating to Cloud services 1.1.3 from 1.1.2
This topic describes the procedure for upgrading to Cloud services 1.1.3 from 1.1.2. - Migrating to Cloud services 1.1.3 from 1.1.0 and 1.1.1
This topic describes the procedure for upgrading to Cloud services 1.1.3 from 1.1.0 or 1.1.1. - Migrating to IBM Cloud Object Storage software level 3.7.2 and above
If you have used IBM Cloud Object Storage software level system (3.7.x and below) as the cloud storage tier for some time and then upgraded to IBM Cloud Object Storage software level 3.7.2 or above, you must perform certain configurations. This is required because of a change in computation of the entity tag (ETag) in IBM Cloud Object Storage software level 3.7.2. - Completing the migration to a new level of IBM Spectrum Scale
It is a good idea to use the cluster for a while with the new level of IBM Spectrum Scale installed, until you are sure that you are ready to permanently migrate the cluster to the new level. - Reverting to the previous level of IBM Spectrum Scale
If you decide not to continue the migration to the latest level of GPFS, and you have not yet issued the mmchfs -V command, you can reinstall the earlier level of GPFS. - Coexistence considerations
Each GPFS cluster can have multiple GPFS file systems that coexist on the cluster, but function independently of each other. In addition, each file system might have different data management programs. - Compatibility considerations
All applications that ran on the previous release of GPFS will run on the new level of GPFS. File systems that were created under the previous release of GPFS can be used under the new level of GPFS. - Considerations for IBM Spectrum Protect for Space Management
Migrating to GPFS 3.3 or beyond requires consideration for IBM Spectrum Protect for Space Management. IBM Spectrum Protect for Space Management requires that all nodes in a cluster are configured with a DMAPI file handle size of 32 bytes. - GUI user role considerations
When the IBM Spectrum Scale is updated from 4.2.0.x to 4.2.1, no default group is created for the user role User Administrator. - Applying maintenance to your GPFS system
Before applying maintenance to your GPFS system, there are several things you should consider.
Parent topic: Installing and upgrading