Subject: Re: Nfs clients get frozen when NFS server crashes...
To: Sam <sam@epita.fr>
From: Manuel Bouyer <bouyer@antioche.lip6.fr>
List: netbsd-users
Date: 10/03/2000 18:10:52
On Tue, Oct 03, 2000 at 06:03:29PM +0000, Sam wrote:
> I know that. But we dont want to use a new major release, we wait til 1.5.1 or 1.5.2...
> We had to much trouble with 1.4.0...

I have a NFS server running 1.5_ALPHA without problems:
armandeche:/home/NetBSD-1.5/src/sys/net>rup disco
disco                    up  82 days,   5:49,  load average: 2.39 2.72 2.81

ALPHA ds20, 20 disks connected to 4 NCR 875 (raid 1), netgear gigabit
interface, serving 15 solaris and 50 linux/windows machines.

At last it's better than FreeBSD requiring a daily reboot :)

> 
> > 
> > > 
> > > We have a problem now with the freeBSD servers, which nfsd process stops every day...
> > > When this hapenns all the netbsd clients that try to access the exported file systems 
> > > which are not accessible, get stuck, and sometimes get completely frozen.
> > > 
> > > Here is how they are mounted:
> > > 
> > > (sam@jotun 42)cat /etc/fstab
> > > /dev/wd0a / ffs rw 1 1
> > > /dev/wd0b none swap sw 0 0/kern /kern kernfs rw
> > > /proc /proc procfs rw
> > > hermes:/space/mail  /nfs/hermes/mail nfs nosuid,nodev,rw,soft,bg,intr 0 0
> > > s1:/space/export    /nfs/s1/space    nfs nosuid,nodev,rw,soft,bg,intr 0 0
> > > s2:/space/export    /nfs/s2/space    nfs nosuid,nodev,rw,soft,bg,intr 0 0
> > > s3:/space/export    /nfs/s3/space    nfs nosuid,nodev,rw,soft,bg,intr 0 0
> > > s4:/space/export    /nfs/s4/space    nfs nosuid,nodev,rw,soft,bg,intr 0 0
> > > s5:/space/export    /nfs/s5/space    nfs nosuid,nodev,rw,soft,bg,intr 0 0
> > > 
> > > We then have to reboot the 500 clients each time the servers crashes...
> > > It's really annoying and shouldn't happen.
> > 
> > Do the client use TCP or UDP mount ? Try to force UDP mounts.
> > If this doesn't solve the problem, use tcpdump on the server after a reboot
> > to see if the client tries to talk to the server, and if the server replies.
> 
> I dont know if it uses udp or tcp, i'll check that, is there an option to mount 
> to tell wether to use UDP or TCP ?

'man mount_nfs'. 

> I'll do the tcpdump stuff also..

You can also check with tcpdump if the client uses TCP or UDP ...

--
Manuel Bouyer, LIP6, Universite Paris VI.           Manuel.Bouyer@lip6.fr
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