topic Can we calculate the aggregate snapshot reclaimable space in ONTAP Discussions

Can we calculate the aggregate snapshot reclaimable space

bondbhola — Thu, 05 Jun 2025 06:03:51 GMT

Hi Technical experts..

Can we calculate the aggregate snapshot reclaimable space?

Please share your view here.

Regards,

Bhola

Re: Can we calculate the aggregate snapshot reclaimable space

BALAJI_VENKATRAMAN — Mon, 29 Apr 2013 13:10:18 GMT

You can do df -Ag <aggregate-name> and you can get the space taken by Aggregate snapshots.

Aggregate total used avail capacity

aggr4_thin_DONOTUSE 14342GB 7747GB 6594GB 54%

aggr4_thin_DONOTUSE/.snapshot 0GB 0GB 0GB ---%

Hope this answers your questions

Re: Can we calculate the aggregate snapshot reclaimable space

bondbhola — Mon, 29 Apr 2013 13:16:12 GMT

Hi Balaji,

If we have many snapshot for aggregate, if i want to see one snapshot space utilzation ( like snap reclaimable command) then how this can be done.

Regards,

Bhola Gond

Re: Can we calculate the aggregate snapshot reclaimable space

RAVI_PALADUGU — Mon, 29 Apr 2013 13:42:01 GMT

Hi Bond,

You can use the 'snap delta -A <aggr name>' to look at the space utilization (delta) of each snapshot of a aggregate.

Best

Re: Can we calculate the aggregate snapshot reclaimable space

bondbhola — Mon, 29 Apr 2013 13:47:41 GMT

snap delta -A <aggr name>' will show the delta space of snapshot not the total space of snapshot..

Re: Can we calculate the aggregate snapshot reclaimable space

BALAJI_VENKATRAMAN — Mon, 29 Apr 2013 13:50:47 GMT

eg-nastest-e10> df -Ag
Aggregate                total       used      avail capacity
aggr1_thin             21514GB      220GB    21293GB       1%
aggr1_thin/.snapshot        0GB        0GB        0GB     ---%
eg-nastest-e10> snap list -A
Aggregate aggr1_thin
working...

%/used       %/total date          name
---------- ---------- ------------ --------
0% ( 0%)    0% ( 0%) Apr 29 13:26 test.1
0% ( 0%)    0% ( 0%) Apr 29 13:26 test.0

I created 2 snapshots on the aggregate and checked snap delta -A and the difference between the snaps is displayed.

test-filer> snap delta -A aggr1_thin test.1

Aggregate aggr1_thin
working...

From Snapshot To KB changed Time Rate (KB/hour)
--------------- -------------------- ----------- ------------ ---------------
test.1 Active File System 28232 0d 00:02 826302.439

This does not seem to be that accurate in calculating the space taken by the snapshot.

Re: Can we calculate the aggregate snapshot reclaimable space

bondbhola — Mon, 29 Apr 2013 13:58:00 GMT

Below is the concept of snap delta. this will show the change in snapshot. it will not show the actual total size of snapshot.

snap delta [ vol_name [ snapshot-name ] [ snapshot-name ]]
Displays the rate of change of data between snapshots. When used without any arguments it displays the rate of change of data between snapshots for all volumes in the system, or all aggregates in the case of snap delta -A. If a volume is specified, the rate of change of data is displayed for that particular volume. The query can be made more specific by specifying the beginning and ending snapshots to display the rate of change between them for a specific volume. If no ending snapshot is listed, the rate of change of data between the beginning snapshot and the Active File System is displayed.

The rate of change information is displayed in two tables. In the first table each row displays the differences between two successive snapshots. The first row displays the differences between the youngest snapshot in the volume and the Active File System. Each following row displays the differences between the next older snapshot and the previous snapshot, stepping through all of the snapshots in the volume until the information for the oldest snapshot is displayed. Each row displays the names of the two snapshots being compared, the amount of data that changed between them, how long the first snapshot listed has been in existence, and how fast the data changed between the two snapshots.

The second table shows the summarized rate of change for the volume between the oldest snapshot and the Active File System.

snap delta run on a volum

Re: Can we calculate the aggregate snapshot reclaimable space

BALAJI_VENKATRAMAN — Mon, 29 Apr 2013 14:10:03 GMT

I did a "priv set advanced"te and priv set diag as well but no additional options were available to check the space consumed by one aggregate snapshot.Please share if you come across any options

I think the reason being - that unlike volume snapshots which are stitched together i.e related to each other by changed blocks through pointers.

May I know exactly what are you trying to accomplish by finding this info.Are you trying any restore as such??

Re: Can we calculate the aggregate snapshot reclaimable space

RAVI_PALADUGU — Mon, 29 Apr 2013 14:10:32 GMT

That is correct, it is very intuitive that you can do a simple math to know the size of snapshot. Not sure what else you are looking for.

Re: Can we calculate the aggregate snapshot reclaimable space

RAVI_PALADUGU — Mon, 29 Apr 2013 14:19:05 GMT

If you run powershell, you can use this.

PS C:\> get-nasnapshot -TargetName aggr0 -TargetType aggregate

Name Created Total Cumulative Dependency

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

hourly.0 4/29/2013 10.7 GB 10.7 GB

hourly.1 4/28/2013 1.1 GB 13.8 GB

hourly.2 4/28/2013 1.4 GB 15.2 GB

hourly.3 4/28/2013 10.3 GB 25.5 GB

nightly.0 4/29/2013 2.0 GB 12.7 GB

Hope that answers your question!

Best,

Re: Can we calculate the aggregate snapshot reclaimable space

bondbhola — Mon, 29 Apr 2013 14:56:57 GMT

Its just for knowledge purpose.