My organization recently bought a storage system. It has 1.5Petabyte, with RAID6, and there is an online synced mirror in a physical different location.
The system allows rollback / file recovery, by default allowing up to 30 days but this can be increased.
There is a discussion going on if we need some kind of extra backup for data living only on the storage.
The system has a very good level of redundancy, it has geographical redundancy and allows up to some extent rollback which means we can recover up to the defined time (30 days by default) old data or accidentally deleted data.
Given this scenario does it still make sense to have a "traditional" backup?
By traditional, I mean a dedicated backup system, with snapshots that we can retrieve in case something goes wrong.
Do we really need it? Am I missing something? Am I just thinking by the traditional way and being over zealous?
Best Answer
What you describe is essential a geographically distributed RAID and a RAID was never a backup.
Online sync usually means everything you do on the primary storage gets immediately replicated to the backup system, including operations like the deletion of (all) snapshots and/or volumes by an attacker or simply an admin error.