topic Re: ASIS and oversubscription in ONTAP Discussions

ASIS and oversubscription

dstrebel — Thu, 05 Jun 2025 07:27:00 GMT

Currently we are using ASIS on for our VMware volumes. Is there a guide or best practice on how much space you should pad when oversubscribing.

Re: ASIS and oversubscription

radek_kubka — Wed, 17 Jun 2009 20:02:36 GMT

What do you mean by that - oversubscription due to thin provisioning? Are you using NFS or LUNs?

It may or may not have anything to do with de-dupe.

Ideally you shouldn't oversubscirbe on the aggregate level - if you do than close monitoring is highly recommended.

If volumes are not thinly provisioned then setting them to autogrow makes sense.

Regards,
Radek

Re: ASIS and oversubscription

dstrebel — Wed, 17 Jun 2009 20:41:10 GMT

Yes due to thin provisioning. We set are luns for thin provisioning. We are oversubscribing at the volume level.

Re: ASIS and oversubscription

radek_kubka — Wed, 17 Jun 2009 20:51:53 GMT

So definitely set volume auto-grow on & (probably) snapshot auto-delete on as well.

And monitor space usage closely

BTW - you may find Chris' post useful as well - although is mainly about fractional reserve, somewhere in the middle of the comments there is his howto guide about setting volumes to auto-grow, etc.

http://communities.netapp.com/groups/chris-kranz-hardware-pro/blog/2009/03/05/fractional-reservation--lun-overwrite

Regards,
Radek

Re: ASIS and oversubscription

amiller_1 — Thu, 18 Jun 2009 18:13:09 GMT

If possible, I might seriously look at using NFS -- some thoughts here.

http://communities.netapp.com/message/8822#8822

Specifically with dedup, you'll see the space savings immediately -- no thin provisioning or any other steps required.