When deploying the Continuous Availability feature of the new File Server clusters in Windows Server 2012, be careful not to use volumes that have either 8.3 naming or NTFS compression enabled.

If you have these features enabled on the volume, the File Server won’t be able to properly track the ongoing operations on the volume using the Resume Key Filter and Continuous Availability won’t work.

You might see this issue in the SMB Server event log as event ID 1801: “CA failure - Failed to set continuously available property on a new or existing file share as Resume Key filter is not started.”

You will also see an associated error in the the ResumeKeyFilter event log: event ID 1008: “The filter failed to attach to a volume because the volume supports short names but the filter does not support short names.”

To fix this issue, you need to disable 8.3 naming and NTFS compression on the volumes to be used on those File Server clusters.

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