Limit FlexVol size FAS2020

[millersysjpalumbo]

Hi All,

We have a FAS2020 as our storage backend for Citrix XenServer with XenServer Essentials.

XenServer Essentials has a nifty little app called StorageLink which basically manages our storage entirely for us. Basically, we tell it to create a group of FlexVols (1-32) and it automatically creates LUNs for each VM that we spin up. It uses ONTAP for snapshots, fast clones, etc. It's really cool.

My question deals with the relationship between the FlexVol size, and deduplication limits.

According to some NetApp doc that I read, the FAS2020 can create FlexVols greater than 1TB, but they cannot be deduped unless they are under 1TB. Is that correct? If so, I need to be able to make sure my FlexVols don't get above that limit, as I definitely need to leverage deduplication in my environment. The aggr is about 2TB and the Citrix StorageLink software will just grow the FlexVol until it can't anymore.

Is there any way to limit a FlexVol at 1TB, or any arbitrary number? Or, is my understanding of this 1TB limit off? For example, is 1TB a hard limit for the FlexVol size on a FAS2020?

Many thanks!

[lrhvidsten · Accepted solution]

It depends on your ONTAP version:

ONTAP 7.3 or earlier: 500GB - If the FlexVol has been larger than 500GB, then deduplication cannot be enabled on that volume, even if it is shrunk to a size supported by the storage system. A new compliant volume must be used.

ONTAP 7.3.1 or later: 1TB - FlexVol can be shrunk down from a larger size to meet threshold.

For the current 7.3.3 GD release, refer to this page:

http://now.netapp.com/NOW/knowledge/docs/ontap/rel733/html/ontap/smg/GUID-2FD76C49-08CE-47BA-972D-E0F578DF6575.html