Handling Heavy Write Loads on RHEL5

If you are operating on RHEL5 and have a heavy NFS write load, you might experience resource contention between the NFS client and the NFS server. This resource contention can cause the NFS server to be unresponsive. To avoid this potential problem, try one of these approaches:

  • Edit /etc/sysctl.conf and apply these settings on each NFS server:

    vm.dirty_ratio=10
    vm.dirty_background_ratio=5

    Reboot the server so the changes will take effect. To make the settings take effect immediately, issue the echo command as shown:

    % echo 10 > /proc/sys/vm/dirty_ratio
    % echo 5 > /proc/sys/vm/dirty_background_ratio
  • Separate the NFS client from the NFS server so they do not compete for memory on the same system.