Is there a way to expire snapshots more often than daily?

[andrew_griffiths]

I'm attempting to setup a consistency group snapshot of an Oracle database. The recovery at present is only expected to be crash consistent, so I am not tying in other features such as database quiesceing or suchlike. First of all I just want to get the snaps done and then snapmirrors following.

I am running snapcreator from the OS cron at 10 minute intervals. Basing my retention period around 1 day (NTAP_SNAPSHOT_RETENTIONS=hourly:1 NTAP_SNAPSHOT_RETENTION_AGE=1) I'm going to have 144 snapshots present before the oldest of them is eligible to be deleted. I'm aware that hourly is purely a policy name, not having an influence on the retention UOM.

A couple of my volumes are small, but with a high level of churn, so I'm concerned that I'm going to run out of space in my snapshot reserve well before 24 hours is up.

The unit of measure for NTAP_SNAPSHOT_RETENTIONS is a day as documented, but what I'd like to know is there any way that the retention period can be specified as a smaller period, say an hour, or maybe a feature for future releases, or is there any way someone's already employed to prune unwanted snapshots in a POST_NTAP_DATA_TRANSFER_CMD## or POST_NTAP_CMD## ? snapcreator--action delete appears to be completely interactive, is there another API way?

All suggestions gratefully received.

[ktenzer · Accepted solution]

Hi There,

Two things

1. Retention Age can be less then a day. Here is example of setting it to half a day:

NTAP_SNAPSHOT_RETENTION_AGE=.5

You can use a decimal to indicate less than a day

2. Since you only seem to care about deleting by snapshot agent number number + age I recommend setting the following parameter

NTAP_SNAPSHOT_DELETE_BY_AGE_ONLY=Y

As for non-interactive. SC 3.4.x doesnt have non-interactive mode but in SC 3.5.0 you will get non-interactive and can delete snapshots or do restores non interactively with the --non_interactive option. SC 3.5.0 will release on Jan 12 2012.

If you are a partner you can get access to the Snap Creator Developer Community, we have released an early version of 3.5.0 but it comes with NO NGS support, so I just recommend this for testing, etc unless you are ok with community support and dont require NGS.

We are working on making this available to customers, there are some technical issues but hopefully it will be open to customers soon

www.snapcreator.com

Regards,

Keith

[andrew_griffiths]

Hi Keith,

Thanks for the very prompt answer. I'll try that out tomorrow and mark your answer as correct. It hadn't occurred to me to try a decimal! Otherwise I'll wait patiently for 3.5.0.

Regards

Andy

[andrew_griffiths]

Did the job thanks.

NTAP_SNAPSHOT_RETENTION_AGE=0.02 cleans up after roughly 30 minutes in my every 10 minute cycle.

Andy

[ktenzer]

Great news thanks for replying back!

Have a great weekend too

Keith