Effect of changing volume accessibility by volume relocation

Products

• VMware vCenter Server

Issue/Introduction

Symptoms:

Post relocation of FCDs attached to powered on VM, such that it's dissociated from profile on relocation. Health information received might be incorrect/unexpected - "DatastoreAccessibilityStatus" shows inaccessible.

Environment

VMware vCenter Server 8.0.x

Cause

• During post-provisioning callback of spbm, VPXD sends the following information ((Vm, Diskid), ProfileId). SPBM checks if the disk whose association needs to change is FCD or not, if FCD it persists the following info as fcdInfo (fcdId, DatastoreMoRef, profile etc). To compute and persist FcdInfo of attached FCDs, SPBM invokes a property collector call of VM and it’s properties.

• During post-provisioning-callback of a POWERED ON VM, the property collector might return stale data i.e. datastore fields of disk might still point to source datastore.  SPBM calculates Compliance of FCD based on the persisted fcdInfo. Since fcdInfo is corrupted, SPBM computes an invalid Compliance and health for the object (as the backing object id of disk cannot be retrieved with wrong fcdInfo) till FcdInfo is fixed (this happens only when a operation which updates FcdInfo is executed - applyAssociated, updating FCD profile, etc).

Resolution

VMware introduced new vmodl field to DissociateOp. As part of post-callback VPXD sets destination datastore in DissociateOp.hub field.
If DissociateOp.hub is set, then SPBM sets datastore passed in DissociateOp in FcdInfo. 

VMware is aware of this issue and will be fixed in the future release of vSphere 8.0.