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Problem with agregate free space and snapmirroring

Hello everybody.

I've got 2 FAS 2220 with 8.1.1 7-mode.

I activated asynchronous snapmirroring (on nfs_logs) , and it's working fine, but I can see that agregate free space is going down.

The first time (before snapmirroring), the output was like it:

aggr show_space -h

Aggregate 'aggr0'

    Total space    WAFL reserve    Snap reserve    Usable space       BSR NVLOG           A-SIS          Smtape

           24TB          2479GB             0KB            21TB             0KB             0KB             0KB

Space allocated to volumes in the aggregate

Volume                          Allocated            Used       Guarantee

vol0                                173GB          4258MB          volume

nfs_logs                             21TB           105MB          volume

Aggregate                       Allocated            Used           Avail

Total space                          21TB          4363MB           626GB

Snap reserve                          0KB            0KB             0KB

WAFL reserve                       2479GB            18GB          2460GB

Now :

aggr show_space -h

Aggregate 'aggr0'

    Total space    WAFL reserve    Snap reserve    Usable space       BSR NVLOG           A-SIS          Smtape

           24TB          2479GB             0KB            21TB             0KB             0KB             0KB

Space allocated to volumes in the aggregate

Volume                          Allocated            Used       Guarantee

vol0                                173GB          4653MB          volume

nfs_logs                             21TB          8425MB          volume

Aggregate                       Allocated            Used           Avail

Total space                          21TB            12GB           614GB

Snap reserve                          0KB            11GB             0KB

WAFL reserve                       2479GB            18GB          2460GB

I dont't understand why snap reserve is growing, because agregate scheduling isn't working:

snap sched -A

Aggregate aggr0: 0 0 0

Thanks

Re: Problem with agregate free space and snapmirroring

Hello,

Could you give ; df  -Ah and snap list -A

Re: Problem with agregate free space and snapmirroring

Hello Said,  this is the output:

df -Ah

Aggregate                total       used      avail capacity

aggr0                     21TB       21TB      614GB      97%

aggr0/.snapshot            0GB       11GB        0GB     ---%

and :

snap list -A

Aggregate aggr0

working...

  %/used       %/total  date          name

----------  ----------  ------------  --------

17% (17%)    0% ( 0%)  Nov 30 09:00  hourly.0

20% ( 4%)    0% ( 0%)  Nov 30 00:00  nightly.0

22% ( 4%)    0% ( 0%)  Nov 29 19:00  hourly.1

25% ( 3%)    0% ( 0%)  Nov 29 14:00  hourly.2

27% ( 4%)    0% ( 0%)  Nov 29 09:00  hourly.3

Re: Problem with agregate free space and snapmirroring

strange !!!!

Could you verify the date at which you disabled the aggragat snap sched ?

Is there any script taking this snap ?

If no , delete this snap and observe what is going to take place.

Re: Problem with agregate free space and snapmirroring

I disabled agregate snap sched on Nov 30, to see if agregate snapshots will be the same size in the future or not.

But i noticed that it was the same problem and agregate snapshot are using more and more space, so the agregate free space is goig down, whereas no agregate scheduling is active.

Re: Problem with agregate free space and snapmirroring

OK.

Snapshots  keep track of the blocks that have changed  between snapshots and the current filesystem. The  changes  introduce to a filesystem can  increases  the snapshot size.

If you dont' need those snap, delete them.

Re: Problem with agregate free space and snapmirroring

Thanks Said.

I deleted all existing agregate snapshots, I'll see tomorow if somme agregate snapshots will be generated or not.

I hope "no".

Re: Problem with agregate free space and snapmirroring

All is ok now, no more agregate snapshots arre generated.

Thanks you Said.

Re: Problem with agregate free space and snapmirroring

Also note that when you delete aggregate snapshots, not all blocks are freed immediately. There's a WAFL scan running to reclaim the freed aggregate blocks ... This may distort any "df -A" or "aggr show_space" figures you look at.