Professionals related to the world of backup and disaster recovery will easily know the difference between Failover and Failback. But to those who are new the world of data storage and are interested in having a bit of knowledge, here’s the article which can guide you through the basics.
Failover is the process of shifting I/O and its processes from a primary location to a secondary disaster recovery location. This typically involves using a vendor’s tool or a third party tool of some type that can temporarily halt I/O, and restart it from a remote location.
The whole process will temporarily halt I/O suspending data copying and mirroring activity that may be going on from the primary location to the secondary location. This will then bring applications and I/O up from that remote location.
During the said activity at the remote site, changes occurring are usually tracked to later synchronize and restore to service by just replicating the data between the start and end of the DR event back to the primary location when it comes to backup.
Failback is the process of re-synchronizing that data back to the primary location, halting I/O and application activity once again and cutting back over to the original location.
In simple words- The failover operation is the process of switching production to a backup facility (normally your recovery site). A failback operation is the process of returning production to its original location after a disaster or a scheduled maintenance period.