Validate Storage Spaces Persistent Reservation Test Results with Warning

I have seen questions from customers who get a warning in the results of their failover cluster validation that indicates the storage doesn’t support persistent reservations for Storage Spaces. They want to know why they got the warning, what it means, and what should they do about it. First, here is the text you will see in the report from the failover cluster validation.  It will be highlighted in Yellow and the test may have a Yellow triangle icon next to it:

Validate Storage Spaces Persistent Reservation

Validate that storage supports the SCSI-3 Persistent Reservation commands needed by Storage Spaces to support clustering.

Test Disk <number X> does not support SCSI-3 Persistent Reservations commands needed by clustered storage pools that use the Storage Spaces subsystem. Some storage devices require specific firmware versions or settings to function properly with failover clusters. Contact your storage administrator or storage vendor for help with configuring the storage to function properly with failover clusters that use Storage Spaces.

Question: Why did I get this warning?

Failover Clustering requires a specific set of SCSI-3 persistent reservation commands to be implemented by the storage so that Storage Spaces can be properly managed as clustered disks.  The commands that are specifically needed for Storage Spaces are tested, and if they are not implemented in the way that the cluster requires, this warning will be given. 

Question: What does this mean and why is it a warning and not a failure?

Failover cluster has multiple tests that check how the storage implements SCSI-3 persistent reservations.  This particular test for Storage Spaces is a warning instead of a failure because clustered disks that aren’t going to use Storage Spaces will work correctly if the other SCSI-3 persistent reservation tests pass.

Question:  What should I do when I get this warning?

To be compatible with Storage Spaces it requires support for the additional PERSISTENT RESERVE OUT Register (00h) persistent reservation command, if you are not using Storage Spaces with this cluster (such as on a SAN) then this test is not applicable and you can ignore any results of the “Validate Storage Spaces Persistent Reservation” test including this warning.  To avoid future warnings, you can exclude this test.

If you intend to use the disks with Storage Spaces on the cluster they not compatible and you should check your storage configuration and documentation to see if there are settings or firmware/driver versions required to support clustered storage spaces.   

The following note is in the KB article that states the support policy for Windows Server 2012 failover clusters.  The yellow yield sign mentioned is referring to a warning in the validation test results.

Note The yellow yield sign indicates that the aspect of the proposed failover cluster that is being tested is not in alignment with Microsoft best practices. Investigate this aspect to make sure that the configuration of the cluster is acceptable for the environment of the cluster, for the requirements of the cluster, and for the roles that the cluster hosts.

Here are some links to more information regarding clustered storage spaces, cluster validation, and the support policies regarding the validation tests:

Steven Ekren
Senior Program Manager
Windows Server Failover Clustering