We several WebSphere application servers logging to a central NFS mount. Both the app servers and the NFS server are running in VMWare, the app servers are RHEL 5, and the NFS server is Ubuntu 8.04. All servers are connected via gigabit ethernet, at a minimum. We are experiencing random corruption of the logs, where there will be large amounts of white space in them. We used to mount directly to a NetApp server, but migrated to this setup. The NetApp doesn't have this problem.
On the NFS server, I've set the following sysctl commands:
sysctl -w net.ipv4.tcp_wmem="4096 87380 8388608" sysctl -w net.ipv4.tcp_rmem="4096 87380 8388608" sysctl -w net.ipv4.tcp_sack=0 sysctl -w net.ipv4.tcp_dsack=0 sysctl -w net.ipv4.tcp_max_syn_backlog=8192 sysctl -w net.ipv4.tcp_synack_retries=3 sysctl -w net.ipv4.tcp_retries2=5
The filesystem is exported with this command in /etc/exports:
And mounted with this command on the app servers:
mount -t nfs -o rsize=8192,wsize=8192 192.168.0.1:/srv/export/logs /webspherelogs/