topic Re: Volume size is larger than the aggregate used space in ONTAP Discussions

Volume size is larger than the aggregate used space

Julien_Mos — Wed, 04 Jun 2025 09:50:23 GMT

Hello,

I have created two 8TB aggregates on which there are two 8TB volumes that are nicely full.

If I go to my aggregates, Ontap tells me that they are half full.

My question :
Can I add space to my volumes so that they are more than 8TB?
Isn't this going to be a problem?

Thank

Re: Volume size is larger than the aggregate used space

Ontapforrum — Fri, 21 Apr 2023 10:26:14 GMT

Could you share the screenshot of the aggr/volume space or CLI output ?

If the Volume is Thin Provisioned, then of course you can, this concept is called 'Over/THIN Provisioning'. However, you must monitor your available space in the given aggregate, and add storage to the aggregate as needed to avoid write errors due to insufficient space.

More info on this covered here:
https://kb.netapp.com/onprem/ontap/os/FAQ%3A_Over_Provisioning_aka_Thin_Provisioning_in_ONTAP#:~:text=As%20a%20result%20of%20being%20able%20to%20create,results%20in%20an%20aggregate%20that%20is%20over%20provisioned.

Re: Volume size is larger than the aggregate used space

Julien_Mos — Fri, 21 Apr 2023 11:57:48 GMT

You can find the screen here.

Ok so i think i can grow the size of my volumes.

I gonna check your link and wait your response. 🙂

Re: Volume size is larger than the aggregate used space

paul_stejskal — Fri, 21 Apr 2023 13:18:32 GMT

The second screenshot shows a 15 and 17:1 data efficiency ratio. You're benefiting from ONTAP's ability to save space. This is working as expected 🙂