Solved

Snapshot exclusive usage vs Reclaimable space


Badge +1
Hi team,
I have created a Protection Domain with one VM. I have setup a daily schedule with a retention policy of 5. When I look at the local snapshots, I shows me the last 5 snapshots that are available. This is the same when I tick the box "Include Expired". When I add up the reclaimable space for these 5 snapshots, the total comes to 143.72 MiB. When I look at the value of "Snapshot Exclusive Usage" for the PD, it tells me 492.48 MiB. Why the difference?
On a related question: what is the impact on performance when deleting snapshots? I understand it is a background process, but is there any impact on the protected VM(s) when this is initiated or while it runs?
The environment is running AOS 5.0.1.
Thank you.
Marc.
icon

Best answer by dlink7 8 June 2017, 05:16

Your diagram and assumption of it being swapped around is right. Sorry I have been out of the office this week.

View original

7 replies

Userlevel 4
Badge +20
snapshot exclusive is the data that is specific to that snapshot, i.e., there are no references to vblocks in that vdisk from any other vdisk in the snapshot chain.
reclaimable space: this is the space is going to be higher since this also accounts for vblocks in the vdisk snapshot chain further down that are purely references by just the snapshot (there could be other regions that are referenced by other vdisks further up the snapshot chain)

this number should be equal to or higher than the summation of the above number
Badge +1
Thanks for your reply dlink7, however I am still a bit confused.
First of all, can you review that the descriptions you have given for "snapshot exclusive" and "reclaimable space" indeed belong to these terms? I have a feeling that you swapped them around.

I decided to expand on the drawing that is in the Nutanix bible to try to get to grips with this. See my drawing inline, below.







Can you (or anyone else) have a look to see if the conclusions I draw in the double outlined boxes are correct in relation to reclaimable space and snapshot exclusive usage?

Thank you.

Marc.
Userlevel 4
Badge +20
trying to get some help to confirm somethings. I also think in the UI it should be called PD snapshot exclusive since it seems to be a total.
Badge +1
Hi dlink7,

Did you manage to get some further assistance with this?

Marc.
Userlevel 4
Badge +20
Your right there were swapped around. Your diagram looks good as well. Sorry I have been away from work this week.
Userlevel 4
Badge +20
Your right there were swapped around. Your diagram looks good as well. Sorry I have been away from work this week. Working with docs to get things updated.
Userlevel 4
Badge +20
Your diagram and assumption of it being swapped around is right. Sorry I have been out of the office this week.

Reply