[wplug] NFS problem

[Brian A. Seklecki]

Whoa.  "can't read superblock" from an NFS mount?!  That's crazy.

Are these systems on the same subnet? Any layer 3 devices between them?

Show does "client# showmount -ea [server]" show?

tcpdump has quite a bit of NFS aware packet handling.  Try:

client# sudo tcpdump -s384 -i [iface] -n 'proto \nfs && host server' -vvv

~BAS

On Wed, 23 May 2007, Brandon Kuczenski wrote:

> I am running NFS on a BSD server and Linux client.  Recently (after a kernel 
> oops and a hard reboot) my nfs mounting from the client ceased to work 
> properly.  I can mount one volume, but when I try to mount the second the 
> command hangs.  It doesn't seem to matter which one I mount first-- the 
> second one always fails. If I don't interrupt the hung mount process I get a 
> "can't read superblock" error; restarting portmap on the client fixes the 
> problem.  But I can still only mount one volume.
>
> Nothing has changed on the server for quite awhile.
>
> Any ideas?
>
> The fstab lines I use to mount are:
> server:/home/vol1     /mnt/nfs/vol1  nfs   \
>     rw,nfsvers=3,rsize=8192,wsize=8192,hard,intr    0       0
> server:/usr/local/vol2  /mnt/nfs/vol2 nfs  \
>     rw,nfsvers=3,rsize=8192,wsize=8192,hard,intr    0       0
>
> I've tried it both with and without the 'nfsvers=3,rsize=8192,wsize=8192' 
> options, but I haven't tried any other parameters.
>
> Here is some rpc info with one volume mounted.  It all looks normal:
>
> [server: ]$ rpcinfo -p
>   program vers proto   port
>    100000    2   tcp    111  portmapper
>    100000    2   udp    111  portmapper
>    100005    3   udp    824  mountd
>    100005    3   tcp    796  mountd
>    100005    1   udp    824  mountd
>    100005    1   tcp    796  mountd
>    100003    2   udp   2049  nfs
>    100003    3   udp   2049  nfs
>    100003    2   tcp   2049  nfs
>    100003    3   tcp   2049  nfs
>    100021    1   udp    754  nlockmgr
>    100021    3   udp    754  nlockmgr
>    100021    4   udp    754  nlockmgr
>    100021    1   tcp    914  nlockmgr
>    100021    3   tcp    914  nlockmgr
>    100021    4   tcp    914  nlockmgr
>    100024    1   udp    658  status
>    100024    1   tcp    783  status
> [server: ]$ rpcinfo -p client
>   program vers proto   port
>    100000    2   tcp    111  portmapper
>    100000    2   udp    111  portmapper
>    100024    1   udp    946  status
>    100024    1   tcp    949  status
>    100021    1   udp  32771  nlockmgr
>    100021    3   udp  32771  nlockmgr
>    100021    4   udp  32771  nlockmgr
>    100021    1   tcp  36239  nlockmgr
>    100021    3   tcp  36239  nlockmgr
>    100021    4   tcp  36239  nlockmgr
>
>
> [client: ]# rpcinfo -p
>   program vers proto   port
>    100000    2   tcp    111  portmapper
>    100000    2   udp    111  portmapper
>    100024    1   udp    946  status
>    100024    1   tcp    949  status
>    100021    1   udp  32771  nlockmgr
>    100021    3   udp  32771  nlockmgr
>    100021    4   udp  32771  nlockmgr
>    100021    1   tcp  36239  nlockmgr
>    100021    3   tcp  36239  nlockmgr
>    100021    4   tcp  36239  nlockmgr
> [client: ]# rpcinfo -p server
>   program vers proto   port
>    100000    2   tcp    111  portmapper
>    100000    2   udp    111  portmapper
>    100005    3   udp    824  mountd
>    100005    3   tcp    796  mountd
>    100005    1   udp    824  mountd
>    100005    1   tcp    796  mountd
>    100003    2   udp   2049  nfs
>    100003    3   udp   2049  nfs
>    100003    2   tcp   2049  nfs
>    100003    3   tcp   2049  nfs
>    100021    1   udp    754  nlockmgr
>    100021    3   udp    754  nlockmgr
>    100021    4   udp    754  nlockmgr
>    100021    1   tcp    914  nlockmgr
>    100021    3   tcp    914  nlockmgr
>    100021    4   tcp    914  nlockmgr
>    100024    1   udp    658  status
>    100024    1   tcp    783  status
>
> _______________________________________________
> wplug mailing list
> wplug at wplug.org
> http://www.wplug.org/mailman/listinfo/wplug
>

l8*
 	-lava (Brian A. Seklecki - Pittsburgh, PA, USA)
 	       http://www.spiritual-machines.org/

     "Guilty? Yeah. But he knows it. I mean, you're guilty.
     You just don't know it. So who's really in jail?"
     ~James Maynard Keenan