AMD

NAME

SYNOPSIS

DESCRIPTION

Amd has been designed as a value-added replacement for the SunOS 4 automount(8) program. Considerable design effort has been expended in making amd robust in the face of NFS servers going down. Amd operates by attaching itself as an NFS server to each of the specified directories. Lookups within the specified directories are handled by amd, which uses the map contained in mapname to determine how to resolve the lookup. Generally, this will be a host name, some filesystem information and some mount options for the given filesystem.  

OPTIONS

-n

Normalize hostnames. The name refered to by ${rhost} are normalized relative to the host database before being used. The effect is to translate aliases into ``official'' names.

-p

Print PID. Outputs the process-id of amd to standard output where it can be saved into a file.

-r

Restart existing mounts. Amd will scan the mount file table to determine which filesystems are currently mounted. Whenever one of these would have been auto-mounted, amd inherits it.

-v

Version. Displays version and configuration information on standard error. If you send a bug report, this should be used to determine which version of amd you are using.

-a temporary-directory

Specify an alternative location for the real mount points. The default is /a.

-c duration

Specify a duration, in seconds, that a looked up name remains cached when not in use. The default is 5 minutes.

-d domain

Specify the local domain name. If this option is not given the domain name is determined from the hostname.

-k kernel-arch

Specifies the kernel architecture. This is used solely to set the ${karch} selector.

-l logfile

Specify a logfile in which to record mount and unmount events. If logfile is the string syslog then the log messages will be sent to the system log daemon by syslog(3). This is only available on certain systems (e.g. not HP-UX and early versions of Ultrix).

-t interval.interval

Specify the interval, in tenths of a second, between NFS/RPC/UDP retries. The default is 0.8 seconds. The second values alters the restransmit counter. Useful defaults are supplied if either or both values are missing.

-w interval

Specify an interval, in seconds, between attempts to dismount filesystems that have exceeded their cached times. The default is 2 minutes.

-y domain

Specify an alternative YP domain from which to fetch the YP maps. The default is the system domain name.

-x options

Specify run-time logging options. The options are a comma separated list chosen from: fatal, error, user, warn, info, all.

-D option

Select from a variety of debug options. Prefixing an option with the strings no reverses the effect of that option. Options are cumulative. The most useful option is all. Since -D is only used for debugging other options are not documented here: the current supported set of options is listed by the -v option and a fuller description is available in the program source.

FILES

/a

directory under which filesystems are dynamically mounted

CAVEATS

Symbolic links on an NFS filesystem are incredibly inefficient. Their interpolations are not cached by the kernel and each time a symlink is encountered during a lookuppn translation it costs an RPC call to the NFS server. It would appear that a large improvement in real-time performance could be gained by adding a cache somewhere. Replacing symlinks with a suitable incarnation of the auto-mounter results in a large real-time speedup, but also causes a large number of process context switches.

A weird imagination is most useful to gain full advantage of all the features.  

SEE ALSO

Amd - An Automounter  

AUTHOR

Index

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

FILES

CAVEATS

SEE ALSO

AUTHOR