Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 26 Jul 2014 12:03:52 +0200
From:      Harald Schmalzbauer <h.schmalzbauer@omnilan.de>
To:        Rick Macklem <rmacklem@uoguelph.ca>
Cc:        freebsd-stable <freebsd-stable@freebsd.org>
Subject:   Re: nfsd server cache flooded, try to increase nfsrc_floodlevel
Message-ID:  <53D37D08.2000104@omnilan.de>
In-Reply-To: <2146856958.3199855.1406286842423.JavaMail.root@uoguelph.ca>
References:  <2146856958.3199855.1406286842423.JavaMail.root@uoguelph.ca>

next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 2440 and 3156)
--------------enig356C2EC62062CDEBB8D2BE15
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

 Bez=C3=BCglich Rick Macklem's Nachricht vom 25.07.2014 13:14 (localtime)=
:
> Harald Schmalzbauer wrote:
>> Bez=C3=BCglich Rick Macklem's Nachricht vom 25.07.2014 02:14 (localtim=
e):
>>> Harald Schmalzbauer wrote:
>>>> Bez=C3=BCglich Rick Macklem's Nachricht vom 08.08.2013 14:20
>>>> (localtime):
>>>>> Lars Eggert wrote:
>>>>>> Hi,
>>>>>>
>>>>>> every few days or so, my -STABLE NFS server (v3 and v4) gets
>>>>>> wedged
>>>>>> with a ton of messages about "nfsd server cache flooded, try to
>>>>>> increase nfsrc_floodlevel" in the log, and nfsstat shows TCPPeak
>>>>>> at
>>>>>> 16385. It requires a reboot to unwedge, restarting the server
>>>>>> does
>>>>>> not help.
>>>>>>
>>>>>> =E2=80=A6
>> IMHO such a setup shouldn't require manual tuning and I consider this
>> as
>> a really urgent problem!
>> Whatever causes the server to lock up is strongly required to be
>> fixed
>> for next release,
>> otherwise the shipped implementation of NFS is not really suitable
>> for
>> production environment and needs a warning message when enabled.
>> The impact of this failure forces admins to change the operation
>> system
>> in order to get a core service back into operation.
>> The importance is, that I don't suffer from weaker performance or
>> lags/delays, but my server stops NFS completely and only a reboot
>> solves
>> this situation.
>>
> Btw, you can increase vfs.nfsd.tcphighwater on the fly when it wedges
> and avoid having to reboot.
One suggestion: If raising vfs.nfsd.tcphighwater at runtime solves the
locked nfsserver (which I thought I have tried, but I'm not sure any
more), maybe the log message should reflect that. My first guess was to
look for a systcl named 'nfsrc_floodlevel'. If the log message makes
more sense to contain nfsrc_floodlevel instead of tcphighwater, the
latter should be metioned in the man page anyway.

If the problem is solvable without rebooting, it's a cosmetic problem
IMHO, not that serious show stopper I considered at first. Evereything
but a reboot is fine ;-)

Thanks,

-Harry





--------------enig356C2EC62062CDEBB8D2BE15
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="signature.asc"

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.18 (FreeBSD)

iEYEARECAAYFAlPTfQgACgkQLDqVQ9VXb8jGEgCgsSdlFmMhy8ykYbcyTLdgsUrI
HX4AoJ6f6Rq526YVBy4RXc3iMW2AUpv6
=uqjU
-----END PGP SIGNATURE-----

--------------enig356C2EC62062CDEBB8D2BE15--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?53D37D08.2000104>