2012-07-11 05:19 AM
we are using a FAS3160 with two controllers as failover cluster. We also have a FAS3140 on different location as a snapvault/snapmirorr disaster recovery site.
To protect the system against file loss or system crash we use snapvault to have snapshots on the other site for file recovery purpose (13hourly, 4daily, 4weekly) and snapmirror for an asynchronous snapmirror in 5min intervals.
Now someone from another team brought up an idea. To protect the system against handlings erros on restoring the system in a disater case (resync from older volumes to the actually used volumes) they want us to additionally backing up the primary FAS with a traditional backup on a tape library.
But, why should we do this? I would do this, but I see no benefit to the existing configuation.The system is safe enough. It is used only for file services. But it will cost a tape library plus software plus maintenance.
They argue with higher safety which works well at our top level, but is it necessary to backup up the system twice? Imho not, but maybe I forgot something.
Does anyone have an idea? Does anyone backups from a FAS using CA ARCserve (NDMP NAS Option) or EMC Networker? And why do you do this?
Solved! SEE THE SOLUTION
2012-07-14 09:20 PM
You are partly right , one would not need the tape backup since you have snapvault (For single file restores ) and Snapmirror for full volume restores. But the question is how long are you keeping the snapshots before it gets over written and is the customer is really happy with the retentions set ? he might also be thinking if he wants his data to be kept for a longer period of time then he will have to invest on storage cost at the secondary site. I think here comes the importance of tape backups , if his tape backups are configured in such a way that their retentions are longer than the snapshots (Snapvault backup) then one can definitely take advantage of them and store their data little longer than their snapshots
Tape backups are generally implemented to save cost on your backup to disk infrastructure and by customers who archive their data and store them for longer periods of time.
Other factor would be for compliance reason’s, one will have to save their data no matter what for few years to be complaint with regulation, then they would choose tape rather than disk drives (cost factor)
Yes we do have customers who backup their data to tape via NDMP backup applications such as EMC networker Symantec Netbakcup etc.. the primary reason for them choosing this is compliance and an extra level of protection apart form online backups such as Snapvault and Snapmirror
2012-07-15 09:52 AM
Good discussion... a lot of customers are going with SnapVault to replace or minimize tape... but I still like tape for some reasons. One of my customers has a great saying he calls "administrative misadventure" or a rogue employee. If an employee has access to source and target systems they could destroy the volumes and aggregates. If they only have access to the source system then the snapshots on the target vault could be protected still (at least the ones prior to source "misadventure"). A volume snapmirror could be ruined on the target by deleting snaps and data on the source even without admin access to the target. Not a common thing but something we don't hear that often but is a key reason why my customers keep tape. No matter what an admin does (accident or misadventure) then there are tapes offsite that can be restored... not as a first line which is better with snapvault and snapmirror. The other key reason I agree with too...to keep retention longer than you have enough disk to handle or snap.