Increasing NFS performance

PROBLEM

After 8 concurrent connections to the NFS store, my performance is degraded.

ENVIRONMENT

• On-Premise Server + WebMail Installations: Version 6.0 > Current Version.

CAUSE

By default, the NFS daemon will only spawn up to 8 processes.

RESOLUTION

This can be improved by increasing the RPCNFSDCOUNT value.

1. Open a file called nfs in /etc/sysconfig in your editor
   

   /etc/sysconfig/nfs

2. In the above file, edit the following line to either 32; 64; or 128; depending on the load you experience on your system
   

   #RPCNFSDCOUNT=8

3. Save the changes and restart NFS
   

   /etc/init.d/nfs restart

This can be tested using the following command:

dd if=/dev/zero of=/usr/local/atmail/users/testfile  bs=16k count=1000

If the value returned for transfer speed is less than 1MB/s you should check that your switch and ethernet card, and the disks on the NFS server are optimized.