Performance impact with setting option auth-sys-extended-groups to "enabled" for NFS 16 group limit

GlennMorris — Wed, 04 Jun 2025 12:25:28 GMT

ONTAP 9.3P2, RHEL 7 clients accessing research data. We're facing the NFS 16 group limit and about to enable the auth-sys-extended-groups option for the serving SVM.

We've been asked investigate any performance impact, which seems fairly difficult to quantify with so many variables involved. If anyone has some experience with the workaround, I'd like to hear their thoughts.

Questions:

1) With bypassing the RPC group mask and doing nameservice lookups, is the Vserver NFS Credential Cache still involved?

Will there be any caching involved with the increased lookups?

2) I know "it depends" is involved here, but in general is there any performance of workload A was this prior to enabling, and now performance of workload A appears greatly impacted, minor impact, or same? Not looking for absolute numbers, ever environment is different, but if anyone has some anecdotal information that would be helpful.

3) Has anyone monitored their LDAP/AD servers while making this change to get a sense of impact?

Any information would be appreciated.

Re: Performance impact with setting option auth-sys-extended-groups to "enabled" for NFS

RajeshPanda — Tue, 05 Nov 2019 18:08:19 GMT

@GlennMorris Are you still looking for support?

We are closing this thread, if you are still looking for solution then feel free to update the thread.

topic Re: Performance impact with setting option auth-sys-extended-groups to "enabled" for NFS in ONTAP Discussions

Performance impact with setting option auth-sys-extended-groups to "enabled" for NFS 16 group limit

Re: Performance impact with setting option auth-sys-extended-groups to "enabled" for NFS