NFS Performance Tuning for HP-UX 11.0 and 11i Systems

nfs performance tuning for hp-ux 11.0 and 11i systems page 57

Notes:

Page 57July 22, 2002

What factors influence rpc.mountd

performance?

• The choice of repository used to provide hostname

resolution data (i.e. /etc/hosts, DNS, NIS, NIS+)

Ø How much overhead is involved in getting hostname data

Ø How fast are the directory servers

Ø How accurate is the information in the directory

• The usage and nesting of netgroups for access lists

• The size of the /etc/rmtab file

rpc.mountd

Choice of directory service used for hostname resolution data

HP-UX supports many different hostname resolution repositories – DNS, NIS,

NIS+, and /etc/hosts. Since rpc.mountd depends heavily on hostname

resolution, the speed and accuracy of this data is critical to performance.

The usage and nesting of netgroups for access lists

Netgroups can take a relatively long time to traverse, especially if they are

managed by a directory service such as NIS. Searching netgroups during

every MOUNT request can be burdensome, particularly if the netgroups are

heavily nested. If netgroups are required in your environment, flatten them if

possible.

The size of the /etc/rmtab file

The /etc/rmtab file is used by rpc.mountd to keep track of the filesystems

mounted by each NFS client. mountd reads this file at startup. A large rmtab

file can take several minutes to load, during which time no mount requests can

be processed. This file should periodically be removed during scheduled

maintenance windows.