Synchronous replication writes data to source unit and replicas at the same time, so the primary copy and the replica are always in sync. In the event of a disaster, synchronous replication can provide maximum protection and ensure zero data loss.
Sync. Replication vs. Async. Replication
Synchronous replication is suitable for mission critical applications that require instant failover, but the system design is relatively complex. Asynchronous replication is suitable for a certain delay in copying the data from source unit to target. These two need to be chosen according to the actual situation.
Last sync. of incremental data
0 ~ Very low
Time of next sync
Delay between Source & Target
< 10 ms
No limit, preferably < 1 sec.
Distance between Source & Target
Host Performance Impact
Sync. Replication + C2F Solution
In most cases, volume with Write-back capability has better performance than Write-through. The best practice of volume Write-back plus BBM (Battery Backup Module) solution can reduce the risk of dirty cache.