Snapshot for HP MSA2312fc - need suggestions for better recovery points

[Shakkeer]

I am using HP MSA2012 and we don’t have snapshot option enabled on it, I am planning go for this soon but there few this needs to be clarified 

Volume Mounted to - 4 host

Total Space - 9 TB

Used Space - 5.8

Free Space - 3.8

Free Vdisk Slots - 4

I need to have a good recovery point using snapshot, volumes which is mounted in hosts we are taking backup using DPM's but i need to have one recovery point using snapshot.

1) Can we use tape library for taking snapshots.

2) Can we use low cost NAS ( WD,iOmega..etc) for taking snapshot 

3)Can we consider this as good solution in terms of hardware point of failure ( I mean if entire SAN goes down , i should be able to recover the volume using this snapshot)

4) If incase volume deleted from host , can we mount it back using snapshots.

Finaly , any good suggestion for better recovery pint 

[Patrick Terlisten]

Hello,

taking snapshots of a master volume on a MSA2012 will result in a snapshot on the MSA2012. There is no way to take snapshots of volumes using tape or NAS devices. This is caused by the way how snapshots are taken (pointer copy in the memory of the controller). A snapshot will unaccessable if the MSA fails. But you can use snapshots for recovery if you los data on volumes, or the volume itself.

[Shakkeer]

Hi Patrick,

I really appreceate your quick response , I am really sorry there is a correction I'm using MSA2312fc...

if i understood you correctly we cannot take snapshot using tape library or NAS and the only option is to go for volume snapshot using the same box.  ..I have one more question ,if I have 5 TB volme , how much space will be utlizing for sanpshot?

[Dennis Handly]

>there is a correction I'm using MSA2312fc

(Please use the Post Options > Edit Reply to correct the subjects.)

>4) If in case volume deleted from host, can we mount it back using snapshots.

Yes.

>There is no way to take snapshots of volumes using tape or NAS devices.

Well, you can backup the snapshot.  ;-)

Snapshots are usually for protecting the data from host/application problems.

Or as a source for backups or remote copies.

>how much space will be utilizing for snapshot?

It depends on how much data changes.

[Shakkeer]

Thanks Dennis , I have changed Subject ;D... see below two points from HP engineer ,  does it really make sense??

(Suggestion from HP Engineer)

"if you want to take snapshot of a volume, by default Snap Pool will created with a size of 20% of the volume size.

Snapshot will reside inside the Snap Pool with size of 5MB which mean only pointer will marked but at backup end it will occupies available space of Snap Pool.Snap Pool can Expand but can't reduced, that to its depends on available free space of Vdisk."

Q) Based on above mentioned comment , if I am using  5 TB volume , snapshot occupy only 1 TB space and then it will be growing up gradually depends upon the data changes. 

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(Suggestion from HP Engineer)

" Its depending upon your requirement and investments.But most of the customers prefers Tape Backup rather than Disk Backup for better data reliability(Safe and Security).

NOTE : If it meets your required then please go ahead with NAS Box. "