SnapCreator deletion, retention of Snapshots

[ANDREAS_JANKOWIAK]

Dear all,

we delete Snapshots on our primary storage via  SnapCreator version 3.6.

We have the following settings:

NTAP_SNAPSHOT_RETENTIONS=daily:7

and

NTAP_SNAPSHOT_RETENTION_AGE=7

We want to keep 7 days of Snapshots and min of 7 snapshots.

We have now the following system behaviour:

The system is keeping 8 snapshots, e.g from 2012/12/03 - 2012/12/10.

In the log file we get

[Mon Dec 10 02:22:31 2012] WARN: More than 7 snapshots exist, older snapshots of xxx:earch will be automatically deleted!

[Mon Dec 10 02:22:31 2012] WARN: Deleting Snapshot SAP_E-daily_20121202021500 on xxx:earch

[Mon Dec 10 02:22:32 2012] INFO: Snapshot Delete of SAP_E-daily_20121202021500 on xxx:earch completed Successfully

[Mon Dec 10 02:22:32 2012] WARN: More than 7 snapshots exist (1) but they could not be deleted because they are not older than the retention age (7 days) for

In my opinion this is not correct.

Or am I wrong?

Thanks for your help.

BR,

Andreas

[ktenzer]

Set NTAP_SNAPSHOT_RETENTION_AGE=7 to NTAP_SNAPSHOT_RETENTION_AGE=7.1

Issue is snap is happening at exact time or below so you need to increase retention age just above 7

Keith

[ANDREAS_JANKOWIAK]

Hi Keith,

thanks for your response.  Mhmm at the moment I don't understand your proposal.

We have seven Snapshots Mo - Su. I want to keep 7 days and a minimum of 7 snapshots.

If a new snapshot is created lets say on Monday evening (in the second week) we have 8 days / 8 snaps in the system. After the creation of a snapshot the snapshot deletion is running...

In my opinion it should recognize that we have now 8 snapshots and should delete the oldest one from last monday.  Am I wrong?

I've changed the parameter now to 7.1, but I've the same result. There are still 8 snapshots and I get a warning "SNAPCREATOR More than 7 snapshots exist (1) but they could not be deleted because they are not older than the retention age (7.1 days) for xxxx:ssoft (Config: SAP_S Name: SAP_S Policy: daily)"

Any idea?

Thank you very much.

BR,

Andreas

[ktenzer · Accepted solution]

Sorry try 6.1 or 6.9 not 7.1 (I was thinking backwards).

In my opinion it should recognize that we have now 8 snapshots and should delete the oldest one from last monday.  Am I wrong?

This is exactly what SC does, it says look 8 snapshots and then it checks the oldest snapshot, the 8th and if it is older than the retention age of 7 days it will be deleted. SC is doing this but the age of the snapshot does not appear to be older than 7 days (calculated in seconds). It isnt just any snapshot that is 7 days old, it must be older than 7 days and again we calculate to seconds so it is very accurate which is why having retention above 7 like 6.1 or 6.9 instead of 7 (depending on when backups run / how long they take) is desired. Else you end up with 8 days and 8 snapshots.

Keith

[ANDREAS_JANKOWIAK]

Hi Keith,

thanks again for your help.

This is the solution ;o)

Regards,

Andreas