Powerpath Migration Enabler for Windows: Event Id 1568 Warning from Microsoft-Windows-FailoverClustering after moving a comitted disk resource.

Overview

If you commit a Powerpath Migration Enabler for Windows cluster migration, the source disk's signature will be accessible via a different disk device wwn. This is the intention of the migration. You move data from the source device wwn to the target device wwn, and therefore the device wwn changes.

From Windows Server 2008 R2 onwards, Microsoft Windows FailoverClustering supports "replicated storage" and can therefore tolerate this device wwn change. Microsoft Windows FailoverClustering will however document the fact that such condition occurred (two device wwns with the same signature), by logging event id 1568 (see also https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/dd354024(v=ws.10)?redirectedfrom=MSDN for details).
This event is logged as a Warning, which may in turn raise concerns about any potential impact.

The event id itself is logged before that disk resource is brought online in the cluster on the non-migration node. The message is part of the preparation steps.
If bringing the disk device online succeeds, the internal data structures on the cluster node are updated and the information about the change persists. No further action is required, and the message can be ignored. The "warning" type should be understood as "important Information", as opposed to merely an "information".

Example Messages

Cluster Event Log / Cluster GUI: Showing Event Id 1568 from Microsoft-Windows-FailoverClustering

Cluster Event Log / Cluster GUI: Failover Cluster Manager>Cluster Events: GUI Location

Cluster Event Log / Cluster GUI: Example Message Dump

Log Name: Microsoft-Windows-FailoverClustering/Operational
Source: Microsoft-Windows-FailoverClustering
Date: 2021-03-08T11:51:05.811
Event ID: 1568
Task: Physical Disk Resource
Level: Warning
Opcode: Info
Keyword: N/A
User: S-1-5-18
User Name: NT AUTHORITY\SYSTEM
Computer: testnode-b.testdom.test
Description: 
Cluster disk resource 'Cluster Disk 3' found the disk identifier to be stale. This may be expected if a restore operation was just performed or if this cluster uses replicated storage. The DiskSignature or DiskUniqueIds property for the disk resource has been corrected.

Cluster Log: Showing a corresponding warning record in the operational section

Cluster Log: Section Header

[=== Microsoft-Windows-FailoverClustering/Operational logs ===]

Cluster Log: Example Message

[Operational] 00000b14.00002d88::2021/03/08-11:51:05.811 WARN  Cluster disk resource 'Cluster Disk 3' found the disk identifier to be stale. This may be expected if a restore operation was just performed or if this cluster uses replicated storage. The DiskSignature or DiskUniqueIds property for the disk resource has been corrected.

Logging this message is expected behaviour.

The system has correctly detected that the disk signature now resides on a new device wwn. No action is required.

Debug Notes

Should bringing online of this disk resource unexpectedly fail, then the above specifies the failure location as:

- On the non-migration node;
- After having committed the migration;
- After moving the committed resource from the migration node to the non-migration node, while
- Not having rebooted the non-migration node after that commit.

In this case the event id also merely indicates that the cluster node (correctly!) detected the device wwn change for the respective signature/GUID. As a result, this state must be investigated separately from there. The commit has permanently completed the migration. There is no "undo" of a commit. Therefore you must recover forward and focus on why the disk->online() action fails.