topic Re: Ontap 9.7 supports LUN size >16TB? in AFF

Ontap 9.7 supports LUN size >16TB?

Prabhudev — Wed, 04 Jun 2025 11:01:48 GMT

As per Ontap 9.7 Release Notes, LUN size >16TB is supported. However, when I tried creating LUN of size >16TB, it's still limiting the size to 16TB itself. Is there a different procedure to create >16TB LUN?

If Ontap 9.7 supports it, can anyone provide details on how do we create it?

Re: Ontap 9.7 supports LUN size >16TB?

Ontapforrum — Wed, 08 Jul 2020 21:02:39 GMT

Interesting, could you please share where exactly it is mentioned about LUN size > 16 TB in 9.7 release notes ?

Re: Ontap 9.7 supports LUN size >16TB?

Prabhudev — Wed, 08 Jul 2020 21:22:55 GMT

I think I overlooked at it. In Ontap 9.7 Release Notes, it says...

Removal of LUN resizing to 10 times original size limitation and we can now go up to 16TB.

Ex: Say, original LUN size is 500GB and max resize allowed was only upto 10 times (that is 5TB). But, now we can go upto 16TB irrespective of original LUN size.

So, >16TB LUN is still not possible correct (unless we play with LUN Geometry)?

Re: Ontap 9.7 supports LUN size >16TB?

Ontapforrum — Wed, 08 Jul 2020 21:42:29 GMT

I thought so. Beginning with ONTAP 9.5, you can grow your LUN up to 16 TB regardless of its original size. In ONTAP 9.4 and earlier, you can only grow your LUN to approximately 10 times its original size, but not greater than 16 TB. At present, maximum LUN size remain 16 TB. (In NetApp, LUNs are stored inside a special "file" which in-turn is stored inside the WAFL filesystem, and so are subject to this limit]

Re: Ontap 9.7 supports LUN size >16TB?

Prabhudev — Wed, 08 Jul 2020 21:50:34 GMT

Yes. I am wondering if this limit of 16TB LUN size not going away anytime soon. Or, can we expect the enhancement in the next releases?

Re: Ontap 9.7 supports LUN size >16TB?

Ontapforrum — Wed, 08 Jul 2020 22:15:04 GMT

I guess, this is something only Engineering can address. If you wish, you can reach out to NetApp Tech Support and log a Request For Enhancement (RFE).

Re: Ontap 9.7 supports LUN size >16TB?

SpindleNinja — Thu, 09 Jul 2020 13:28:01 GMT

It is currently in the works. Though i've not heard any firm date.

Re: Ontap 9.7 supports LUN size >16TB?

Prabhudev — Thu, 09 Jul 2020 13:46:27 GMT

Yes, it has been already brought to the NetApp A/c Management. 16TB LUN was big enough few years back but these days, with growing VM size requirements, it's hard with 16TB datastore limitation. I hope to see this limit removed sooner.

Re: Ontap 9.7 supports LUN size >16TB?

Mjizzini — Fri, 10 Jul 2020 03:14:48 GMT

The LUN size is limited to the max file size (16TB). Below are the FlexGroup maximums for Ontap 9.

File size 16TB Hard-coded/enforced
FlexGroup volume size 20PB
File count 400 billion
Cluster node count 24 (12 HA pairs)
NetApp FlexVol member volume size 100TB
FlexVol member volume file count 2 billion

NetApp SnapMirror volume count
(member per FlexGroup)
32 (ONTAP 9.4 and earlier)
200 (ONTAP 9.5 and later)

SnapMirror volume count
(FlexGroup total per cluster)
100 (ONTAP 9.4 and earlier)
6,000 (ONTAP 9.5 and later)

FlexVol member constituent count 200
Aggregate size/count Same as NetApp ONTAP limits

Re: Ontap 9.7 supports LUN size >16TB?

Mjizzini — Fri, 10 Jul 2020 03:18:15 GMT

NetApp ONTAP FlexGroup Volumes Best Practices and Implementation Guide