Re: nfsd becomes a zombie

Chuck Lever III
2024-06-20T19:10:05Z

> On Jun 20, 2024, at 1:29 AM, Harald Dunkel <harald.dunkel@aixigo.com> wrote:
>
> Hi Chuck,
>
> On 2024-06-19 15:14:15, Chuck Lever III wrote:
>> There's no way to answer either of these questions
>> since we have no idea what the problem is yet.
>
> I am getting these messages again, similar to previous
> incidents:
>
> [Wed Jun 19 16:46:14 2024] receive_cb_reply: Got unrecognized reply: calldir 0x1 xpt_bc_xprt 00000000a5ff94a6 xid f9d6a568
> [Wed Jun 19 18:42:23 2024] receive_cb_reply: Got unrecognized reply: calldir 0x1 xpt_bc_xprt 00000000a5ff94a6 xid 59d8a568
> [Wed Jun 19 18:43:15 2024] receive_cb_reply: Got unrecognized reply: calldir 0x1 xpt_bc_xprt 00000000a5ff94a6 xid 5cd8a568
>
> nfsd is still running as usual. Assuming they are related to
> NFS, Is there a way to map these weird messages to a remote IP
> address? I could setup a similar system and use it to capture
> the traffic without breaking privacy.

These messages do come from kernel NFS code, but it's still not
possible to say how they are related to the hang/deadlock.

The best you can do here is enable server tracing:

$ sudo su -
# trace-cmd record -e nfsd:nfsd_cb\*

That will pick up NFSv4 callback related events. When you are
done tracing, ^C.

# trace-cmd report | less

For trace points that record client address information, you
might also need the -R option to see everything in each trace
record.

--
Chuck Lever