ASR(Azure Site Recovery) affecting Avamar .dat files

Hi,

We have Avamar backup setup for our SQL server databases. The databases size are huge. The cumulative backup size is 10TB. Now recently client has setup ASR for disaster recovery and we have started facing blocking issue to our Avamar  backup. We observed that when ASR service start VSS backup start triggering and blocking our Avamar backups, so we are killing those VSS backups. Also, the problem is that previously the Avamar differential backup used to completed within 4 hours now it's taking more than 8 hours and sometimes even more than that and sometimes getting hanged. However, if we do Avamar cleanup by stopping the Backup agent service and deleting all cache .dat files and restart backup agent service then that day the Avamar backups gets completed within 4 hours and of course we are killing VSS backups during the backup process which is blocking the avamar backups. Please help us to resolve the issue permanently.