A DTrace of StorageFileWatch after stopping/starting the Enterprise Vault Storage Service or setting/clearing backup mode of the Vault Store the partition belongs too shows the following:
(StorageFileWatch)<6248>EV:L{CVaultStoreEMCCentera::ClipExists} (Entry)
(StorageFileWatch)<6248>EV:MCVaultStoreEMCCentera::ClipExists -- DisableClipExists: 0 Performing Clip check
(StorageFileWatch)<6248>EV:L{CVaultStoreEMCCentera::PoolOpen} (Entry)
(StorageFileWatch)<6248>EV:MCVaultStoreEMCCentera::PoolOpen - Using existing PoolRef: 298328476355704
(StorageFileWatch)<6248>EV:L{CVaultStoreEMCCentera::PoolOpen} (Exit) Status: [Success]
(StorageFileWatch)<6248>EV:MCVaultStoreEMCCentera::ClipExists -- Calling FPClip_Exists -- Clip-Id: AM4JQTEP996QCe6HMMEC50VFLKEG4197DQ0J3U0KD4L1FOG28OCLT
(StorageFileWatch)<6248>EV:MCVaultStoreEMCCentera::ClipExists -- Returned from FPClip_Exists -- Clip-Id: AM4JQTEP996QCe6HMMEC50VFLKEG4197DQ0J3U0KD4L1FOG28OCLT True
(StorageFileWatch)<6248>EV:L{CVaultStoreEMCCentera::ClipExists} (Exit) Status: [Success]
(StorageFileWatch)<6248>EV:MCVaultStoreEMCCentera::ClipExistsReplica -- Calling FPClip_Exists -- Clip-Id: AM4JQTEP996QCe6HMMEC50VFLKEG4197DQ0J3U0KD4L1FOG28OCLT
(StorageFileWatch)<6248>EV:MCVaultStoreEMCCentera::ClipExistsReplica -- Returned from FPClip_Exists -- Clip-Id: AM4JQTEP996QCe6HMMEC50VFLKEG4197DQ0J3U0KD4L1FOG28OCLT False
(StorageFileWatch)<6248>EV:L{CVaultStoreEMCCentera::ClipExistsReplica} (Exit) Status: [False (0x1)]
(StorageFileWatch)<6248>EV:M{CCenteraItemSecuredVerifier::CheckItem:#79} It took [0.011093] seconds to check clipid [AM4JQTEP996QCe6HMMEC50VFLKEG4197DQ0J3U0KD4L1FOG28OCLT] exists on replica.
Notice that Enterprise Vault performs a ClipExists on the primary node and the result of True is returned. Enterprise Vault also performed a ClipExistsReplica that is returning as False.
In the above Dtrace, it can be seen that Enterprise Vault checks the Primary Centera Node to locate clips and then checks the Secondary (Replica) Node to ensure that the same clip exist. If this check fails, Enterprise Vault will not consider the items within the clip as secured.
As this is typically an issue with replication between the primary node and the secondary node, EMC Support will need to be engaged to confirm if replication has stopped or if there is a delay in replication causing the backlog.