[CentOS] losing NFS connection

Sun Apr 24 19:23:43 UTC 2005
Sean O'Connell <oconnell at soe.ucsd.edu>

On Sun, 2005-04-24 at 20:28 +0200, Angelo Machils wrote:
> Hello there!
> Perhaps this is a little off-topic, but I notice this only on the Centos 
> box.
> I'm running Centos 4 on an AMD64 which has the following entries in the 
> fstab to connect to NFS shares on a Fedora3 box:
> /home/angelo/NFS_share1 nfs 
> rw,addr= 0 0
> /home/angelo/NFS_share2 nfs 
> rw,addr= 0 0
> /home/angelo/NFS_share3 nfs 
> rw,addr= 0 0
> I have opened ports 111 (TCP), 648 (TCP), 651 (TCP) and 2049 (TCP and 
> UDP) in iptables on the FC3 box and I can connect to them, but after a 
> while I seem to loose the connection to the shares.
> When I try to move into them while in a console I get the error:
> bash: cd: NFS_share1: Input/output error
> In Nautilus I don't even see the directories anymore and in 
> /var/log/messages I get this error msgs:
> Apr 24 20:17:02 solaris kernel: RPC: garbage, exit EIO
> There are not entries in the /var/log/messages on the FC3 box.
> If I manually umount them and then mount them again, I can use them 
> again for a while....
> The exports file on the FC3 box looks like this:
> [root at imhotep etc]# more exports
> /home/angelo             192.168.1.*(rw,sync)
> /home/angelo/data        192.168.1.*(rw,sync)
> /home/angelo/data2       192.168.1.*(rw,sync)
> Anyone any idea what is wrong here?


I have found that you need to allow higher numbered tcp ports
(32768:65535) through on both the server and client to make rpc
connections happy. I have also had to allow a range of ports in between
600:1024 UDP range on the server to make things happy (though, this was
with older NFS implementations). It's possible that you need to open up
more ports on the server. One thing to do would be to add a log rule to
your iptables rules on the client and server and see what is being
dropped when the client mount hangs.