Hello, I am experiencing system hangs when running NFSv4 over a tinc VPN. I don't know if the problem is with NFS or tinc and would appreciate any suggestions on how to narrow down the culprit. Unfortunately I cannot simply run NFS directly over TCP -- the participating systems are connected only over an open network. The configuration is as follows: I have a main server that exports the NFS shares and also acts as hub for the VPN. All other clients connect to the main server to establish the VPN, and then mount the NFS shares over the VPN. I am using kernel 3.0.0, 64bit Ubuntu 10.04 LTS on both server and clients. On the server: # cat /etc/exports /srv/nfs4 -ro,no_subtree_check,fsid=root 192.168.1.1/24 /srv/nfs4/home -rw,async,no_subtree_check 192.168.1.1/24 /srv/nfs4/opt -rw,async,no_subtree_check 192.168.1.1/24 /srv/nfs4/hbt -rw,async,no_subtree_check 192.168.1.1/24 On the clients: # cat /etc/hostconf/all/etc/fstab | grep -i nfs spitzer:/opt /opt nfs4 bg 0 0 spitzer:/home /home nfs4 bg 0 0 The problem is that as soon as more than three clients are accessing the NFS shares, any operations on the NFS mountpoints by the clients hang. At the same time, CPU usage of the VPN processes becomes very high. If I run the VPN in debug mode, all I can see is that it is busy forwarding lots of packets. I also ran a packet sniffer which showed me that 90% of the packets were NFS related, but I am not familiar enough with NFS to be able to tell anything from the packets themselves. I can provide an example of the dump if that helps. Any suggestions how I could further debug this? Best, -Nikolaus -- »Time flies like an arrow, fruit flies like a Banana.« PGP fingerprint: 5B93 61F8 4EA2 E279 ABF6 02CF A9AD B7F8 AE4E 425C -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
