In case the Write-Replication network fails
If the write-replication network fails, then VirtuCache keeps trying to replicate writes for 30seconds, during which time writes are not being acknowledged. After the 30 second period, VirtuCache times out the writes. Then VirtuCache freezes IO till the write cache is synced with backend SAN. Since we keep upto 2 minutes of writes in cache, it might take VirtuCache 2 minutes to sync the write cache to the backend SAN. Once the writes are synced to backend SAN, the VMs that were in ‘Write-Back One Replica Mode’ are moved to Write-Through caching mode.
So the maximum duration of IO stoppage could be 2 minutes and 30 seconds.