Replication: Version Requirements and Upgrade Recommendations

IN THIS ARTICLE

Outlines the version requirements and upgrade recommendations for clusters utilizing Continuous Replication in Qumulo Core

REQUIREMENTS

• Source and target cluster running Qumulo Core 2.7.3 or above on any model of Qumulo hardware

DETAILS

Continuous Replication creates a copy of the data in a directory on your cluster and transfers it to a directory on a second target cluster to generate a point-in-time consistent copy of the source directory on the target cluster. Because two clusters are required for this feature, there are specific version requirements and upgrade considerations dependent on what version of Qumulo Core you are running on either cluster. 

Qumulo Core Version Requirements with 2.11.0 and above

Starting with Qumulo Core 2.11.0, clusters using different software versions can still use Replication, up to and including the previous and subsequent quarterly release versions. In other words, a quarterly release like 2.12.0 can replicate with any version of software from 2.11.0 (the previous quarterly) to 2.13.0 (the subsequent quarterly). A non-quarterly release like 2.11.4 can replicate with any version from 2.11.0 to 2.12.0.

See the following additional examples to get a better idea of which versions support cross-version replication:

• 2.11.0 can replicate with any version from 2.11.1 to 2.12.0 (it cannot replicate backwards in this case because the feature was introduced in 2.11.0)
• 2.11.2 can replicate with any version from 2.11.0 to 2.12.0
• 2.12.0 can replicate with any version from 2.11.0 to 2.13.0
• 2.12.3 can replicate with any version from 2.12.0 to 2.13.0

Qumulo Core Version Requirements with 2.10.x and below

To use Continuous Replication with earlier versions of Qumulo Core, the source and target cluster must be running the same version of Qumulo Core 2.7.3 and above. Replication will fail if either cluster is on a different version.

Upgrade Recommendations

No matter what version either cluster is currently running, upgrading Qumulo Core while a replication job is running will cause the job in progress to cancel. Once both clusters return to a state where replication is supported, Continuous Replication can resume. 

If you create a replication relationship with a target directory path specifying the file system root (supported in 2.12.0 and above), there are specific recommendations regarding upgrades. Since the target directory of an established replication relationship is read-only to all client protocol access, upgrading a cluster whose file system root directory is the target of a replication relationship requires the following:

• If the source cluster is available: Copy the upgrade image to a directory on the source cluster (copying it to the read-only target cluster is not allowed) and wait for the upgrade image to be replicated to the target cluster before proceeding with the documented UI or CLI upgrade process
• If the source cluster is unavailable or this is not possible for some reason: Temporarily make the target relationship writable for the duration of the upgrade using the “Make Target Writable” action in the Web UI, and then re-establish the relationship using the “Reconnect Relationship” action after the upgrade completes. Note that this will both interrupt replication for the duration of the process and require additional time to resynchronize the clusters using a full-tree scan after the relationship is reconnected.

IMPORTANT! The first option is recommended whenever possible to avoid having to resync the clusters after a relationship is reconnected.

RESOLUTION

You should now be able to successfully understand the version requirements and upgrade recommendations with Continuous Replication in Qumulo Core

ADDITIONAL RESOURCES

Replication: Continuous Replication with 2.11.2 and above

Replication: Continuous Replication with 2.11.1 and below

Replication: Blackout Windows

QQ CLI: Replication

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