NetWorker 19.7 Snapshot Management Integration Guide

Recover Point is designed in such a way that it takes a snapshot at CG level whenever CGs are used. Networker Snapshot Manager provide users the option to operate at the Individual LUN level inside the CG of Recover Point and take snapshots. It can be recovered by using all the recovery options like file-by-file and Saveset Recovery for both snapshot and Clone backups and Rollback for snapshot backup.

Recover Point Snapshot Restore by Rollback removes snapshots that are created after the snapshot for the LUNs in the same CG, which was used for rollback operation. Due to this behavior, if any LUNs in CG that are used to create separate savesets in Networker and are used in separate policies which are backed up at different time slots, if one of them rollback, there is a chance that the snapshot for other saveset is deleted which are taken after the rollback saveset. Due to this limitation, it is recommended that Recover Point snapshots from NSM should be followed by clone backups to avoid accidental deletion of backup copies in case of a rollback operation for a different saveset. For example, CG1 has 3 LUNs, A,B, and C. Each time Recover Point takes a snapshot, it would be at a CG1 level and not at a individual LUN level. Networker, provides the option to create multiple clients with subsets of these three LUNs (LUN A and B can be part of client 1 and LUN C can be part of Client 2).

Whenever a Networker Snapshot Manager backup is taken for Client 1, Recover Point takes the backup of CG1 and NetWorker would internally use the snapshots of LUNs A and B only. For Client 2 snapshot Recover Point would take snapshot at CG1 and Networker would use snapshot of LUN C.

The user has taken backups of Client A and Client B every 6 hrs, one after other starting at 00 hours, with Client A, and 0600 hours with Client B. There will be 2 snapshots for each client after 24 hours. Now at 1800 hours, there would have been 2 snapshot backups of client A and one snapshot backup of client B. If for some reason, client A data is corrupted just after the first snapshot of Client B (at 0600 hours.) and user chooses to recover using the first snapshot of Client A by means of a rollback, all snapshots taken after 0600 hours will be lost. This is because Recover point would treat all these as CG1 snapshots.

To mitigate this potential risk, it is recommended to take a clone for all the backups, so that the data is not lost.