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

nfs performance tuning for hp-ux 11.0 and 11i systems page 68

Notes:

Page 68July 22, 2002

How are Automount and AutoFS

different from each other? (part 1)

automount

autofs

multi-threaded (in certain places)single threaded

mounts NFS filesystems in-place

uses symbolic links to redirect

pathname lookup requests to

real NFS mountpoints

supports NFS PV3, TCP, CDFS,

CacheFS

supports NFS PV2/UDP only

legitimate filesystempseudo NFS server

Automount AutoFS

The original automounter is only capable of managing NFS protocol version 2

mounts using the UDP transport. AutoFS can manage NFS PV2 or PV3 filesystems

running on top of either UDP/IP or TCP/IP. Additionally, AutoFS can be

configured to manage CacheFS filesystems.

Automount is a single-threaded process that performs its functions of mounting and

unmounting filesystems by emulating an NFS server running on the client system.

This explains why when automount hangs or is slow to respond the client will print

a message similar to one where a remote NFS server stops responding:

NFS server (pid570@/net) not responding still trying

Automount uses symbolic links to redirect pathname requests to the real NFS

mountpoints which it mounts under a holding directory (/tmp_mnt by default).

AutoFS is a multi-threaded daemon which implements a legitimate file system, just

like HFS, VxFS, CDFS, etc. It mounts the filesystems it manages directly to the

requested pathname, avoiding the need for symbolic links.