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CONTAP-226393: SCSI-3 Persistent Reservation (PR) registrations may be inconsistent on vVol-backed Windows Server Failover Cluster (WSFC) shared disks Inconsistency in VMWare ESXi 8.x OS Environments

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Issue

Issue:
In environments using ONTAP with VMware ESXi 8.x OS versions and Windows Server Failover Clustering (WSFC) shared disks on vVol-backed LUNs, SCSI-3 Persistent Reservation (PR) registrations may be inconsistent across LUN paths as seen from host end. In some cases, PR keys are present on only a subset of the LUN paths (often Active/Optimized paths) and missing on others (often Active/Non-Optimized paths).
This may impact WSFC storage operations such as disk failover/ownership changes and can affect cluster availability.
This behavior has been observed with vVol-backed LUNs only and has not been observed with ONTAP LUNs used for VMFS datastores in the same environments.
Cause:
Under certain workflow conditions, PR registration commands (SCSI PR-Out) may receive a Unit Attention (Power-On Reset) response from ONTAP. In the observed scenario, ESXi stroage stack may not reissue PR registration on all affected paths, resulting in PR registrations getting established only on some paths. Hence PR registration shall be missing on the vVols LUN paths where POR UA are received.

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