Re-configuring guaranteed snapshot space (share vs. pool) - Any danger of loosing snapshots?

English Storage
1

Dear all

  • I use one thick provisioned share on my QuTS hero NAS alongside several thin ones.
  • In part due to a misunderstanding, I configured a specific number of 500 gigs of guaranteed snapshot space specifically for that thick share.
  • At the same time I assigned a 20% percentage of guaranteed snapshots space on the pool level

I currently only create snapshots for the mentioned thick share. According to the storage manager, the space needed for these snapshots seems to be allocated/drawn from the guaranteed space of 500 gigs of that specific share (which makes sense). However, due to my setup, the 20% of guaranteed space for the pool remains virtually untouched.

Question: In order to simplify my config I would like to only set guaranteed snapshot space on the pool level (i.e. 20% of the pool) and the snapshots of the thick share to be attributed to this quota of guaranteed space. However, given that the currently existing snapshots “live” on the guaranteed space of the share, what happens if I no longer assign guaranteed space to that share? Will the current snapshots be deleted (worst case)? Or are they simply moved (allocation wise) to the guaranteed space on pool level?

2

As I understand it, guaranteed space means that space is always there for the snapshots. If you remove the guaranteed space, then the space can be used for other purposes. If the NAS needs the storage space, then it will start deleting snapshots. But unless it “needs” that space, you snapshots will be fine.

I’m not sure how the snapshots will be moved, etc. What I would do is clone them to an external drive, do your re-allocation and then move them back if they disappear.

3

Could you please provide detailed screenshots of your settings? This will help us better understand your situation. Thanks!

4

Dear Steve

Here a screenshots of the current config I tried to describe. Thx a lot for your help!

Screenshot Space Snapshots
Screenshot Space Snapshots903×382 43.2 KB

5

Hi @QNAPKnowledge

Adjusting the snapshot guarantee space of a Shared Folder will not affect existing snapshots; the system will migrate the data to the snapshot guarantee space of the Storage Pool.

Thank you