Re: double used hostuuids - Re: NFS issue - newnfs_request: Wrong session srvslot=1 slot=0, freeing free slot!!

Ronald Klop <ronald-lists@klop.ws> wrote:
>On 8/27/22 00:17, Rick Macklem wrote:
>> Ganbold Tsagaankhuu <ganbold@gmail.com> wrote:
>>>> Rick,
>>>>
>>>> On Fri, Aug 26, 2022 at 11:18 AM Rick Macklem > ><rmacklem@uoguelph.ca<mailto:rmacklem@uoguelph.ca>> wrote:
>> Ganbold Tsagaankhuu <ganbold@gmail.com<mailto:ganbold@gmail.com>> wrote:
>>>>> Hi,
>>>>>
>>>>> We are having trouble with NFS running on STABLE:
>>>>>
>>>>> Aug 26 02:21:42 iron2 kernel: newnfs_request: Wrong session srvslot=1 slot=0
>> [stuff snipped]
>>>>> Aug 26 02:22:46 iron2 kernel: newnfs_request: Wrong session srvslot=1 slot=0
>>>>> Aug 26 02:22:46 iron2 kernel: freeing free slot!!
>>>>>
>>>>> We are running FreeBSD 13.1-STABLE #3 stable/13-n252198-c1434fd2dea: Fri Aug 26 01:51:53 UTC 2022 and mount options are:
>>>>>
>>>>> rw,nfsv4,minorversion=1,bg,soft,timeo=20,retrans=5,retrycnt=5
>>>>> ro,nfsv4,minorversion=1,bg,soft,timeo=20,retrans=5,retrycnt=5
>>>>>
>>>>> Is there any fix for this issue?
>> Oh, and one more thing. If you have multiple clients mounting the
>> NFSv4 server, make sure they all have unique hostids.
>> Check /etc/hostid and "sysctl kern.hostuuid". If two clients have the
>> same kern.hostuuid, there will be lots of trouble.
>>
>> rick
>
>
>Just a thought. Is it possible/easy to warn about double used hostuuids >from different client IP addresses?
>Although that will not help this person using Netapp as a server.
I don't think so. Same hostuuid implies same system, so how does a
server know they are two different systems?
- A client could have multiple IP host addresses, so different client
  host IP addresses for a TCP connection does not imply different systems.

I can, however, modify the console message the server generates when
it sees a session has been replaced to include "check clients have
unique hostuuids", which might help.

I also plan on adding a sentence to "man mount_nfs" about this,
since I just had an email discussion with someone else where the
problem turned out to be "same hostuuids for multiple clients"
and the loss of sessions on the FreeBSD server was the hint that
clued me in.

At least I now know this configuration issue exists.

rick

Regards,
Ronald.