2011-10-14 03:06 AM
I'm currently looking to specify a solution based on NetApp storage. I would like to use a NetApp filer on the primary site with a second, smaller NetApp filer at the DR site. Based on my reading, SnapMirror can be used to asynchronously replicate volumes (as snapshots) from the primary to the secondary. I would also like to then take the replicated snapshot on the secondary and snapshot that for backup purposes.
The idea behind this is that in the event of a disaster at the primary site, the secondary site is ready to go (assuming all mirroring is completed). However, for "standard" backup/restore, I'd like the secondary site to store the snapshots even if the equivalent snapshots no longer exist on the primary.
Is this something I can only do with SnapVault (if at all) or is it possible to get this functionality by scheduling snapshots on the secondary?
Does this plan have any obvious flaws (I'm new to this technology!).
Thanks for any pointers.
2011-10-14 03:38 AM
This could be possible with QSM. QSM allows you to have independent snapshot schedules on primary and secondary. Actually you must have snapshot schedule on secondary to actually preserve more than just the latest baseline snapshot.
It is not possible with VSM. VSM replicates the whole volume with all existing snapshots. Destination is read-only, so no additional snapshots can be created. Destination is always exact image of source at the time of last fully transferred snapshot.
2011-10-17 05:17 AM
Quick answer on this is yes you can…exactly what SnapVault is designed for….
You can snapmirror to the secondary and then vault those backups of to a snapvault destination (which can be the same filer, as long as you have all the appropriate licences) .
So although the response about you can’t snapshot the mirrored volumes is correct, nothing stops you vaulting them, although it will create another full copy of the data as part of the vault.
If you just wanted to use snapvault, it could also be done, that in the event of it going horribly wrong in production, you could actually mount the snapvault backups and use them in a Disaster scenario.
Hope that makes sense…and helps a little.
2011-10-21 03:26 AM
To me, the key differentiator between SnapMirror & SnapVault is the process of fail-back:
- Volume SnapMirror is designed in that way that re-synchronisation is straightforward & easy (just reverting the direction of replication), so this is the best tool for site fail-over & fail-back
- you can fail-over to SnapVault target volumes as well, yet the fail-back process will be more complex
So having both methods of data protection ticks all the boxes - SnapMirror caters for DR/BC & SnapVault does mid/long-term backup copies.
What would be really nice, is to have one,"consolidated" target baseline for SnapMirror & SnapVault (two baselines required now & for foreseeable future).