HP-UX 11i Version 2 Release Notes (October 2003)

Disk and File Management
AutoFS
Chapter 5
111
Documentation
The following manpages have changed:
• automount (1M)
• automountd (1M)
The “Configuring and Administering AutoFS” section of the Configuring and
Administering NFS Service manual has changed. Please refer to the NFS product
documentation in the Networking and Communications section of the HP documentation
Web site at http://www.docs.hp.com/.
Obsolescence
AutoFS is the replacement for the Automounter (see “Automounter (Obsolete)” on
page 112), which has been obsoleted from HP-UX 11i v2 forward. All users of this facility
will need to migrate to use AutoFS.
If you were using the old Automounter previously, you should not see any difference
when using AutoFS. Therefore, no migration tool is necessary.
Changes to HP-UX libc Support of AutoFS
The system C library, libc, provides the interface between the user program and the
kernel. (This section covers libc changes to support AutoFS. For other changes to libc,
see “IPv6 Support by HP-UX libc and HP-UX Commands” on page 154.)
Summary of Change
In previous releases, when AutoFS unmounted a filesystem, it obtained the device id
from the filesystem server. If that server were slow, or not responding, there could be a
delay of 15 seconds or more. On systems with many AutoFS-managed filesystems and
many slow or non-responding servers, the cumulative delay could be quite significant.
In HP-UX 11i v2, libc has been changed so that the device id of each mounted file
system is made available in the mounted file system table, /etc/mnttab. As a result,
AutoFS can now pick up the device id of the filesystem to be unmounted from the
/etc/mnttab file instead from the filesystem server, thus improving performance.
Impact
In earlier versions, the option string of each entry in the mounted file system table,
/etc/mnttab, did not have the device id of the mounted file system. Now, with the libc
changes, the option string of each entry of /etc/mnttab will have the device id of the
mounted file system.
While unmounting a filesystem, AutoFS can now get the device id from the /etc/mnttab
file instead from the filesystem server, which leads to performance improvement on
systems with many AutoFS-managed filesystems and many slow or non-responding
servers.
Compatibility
There are no compatibility issues.