Hey Guys,

I had an issue with one of my 7-mode filers (ONTAP 8.1.2) where all of the CPUs were 100% and there was no indication of any volume doing more IOs.

It took down everything on the filer and DBs crashed.

During the issue the output of wafltop show -v cpu:

aggr_sas02_64:prod_volume1:nfsv3:WAFL_READDIR:

consuming 300% CPU

When we checked on the hosts mounting this volume we found out that there was one volume “deploy01” which was migrated to new c-mode filer but the mount was not fixed on those 3 hosts.

So the NFS stack on those 3 servers was hung.

The question now we have is:

1. Why would NFS stale on 3 hosts took down the filer?

2. Is there a BUG around this situation which someone has experienced before?

Any help/clues would be greatly appreciated.

Manish