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hlfsd(8)

NAME

     hlfsd -- home-link file system daemon

SYNOPSIS

     hlfsd [-fhnpvC] [-a alt_dir] [-c cache-interval] [-g group]
	   [-i reload-interval] [-l logfile] [-o mount-options]
	   [-x log-options] [-D debug-options] [-P password-file]
	   [linkname [subdir]]

DESCRIPTION

     hlfsd is a daemon which implements a file system containing a symbolic
     link to subdirectory within a user's home directory, depending on the
     user which accessed that link.  It was primarily designed to redirect
     incoming mail to users' home directories, so that it can read from any-
     where.

     hlfsd operates by mounting itself as an NFS server for the directory con-
     taining linkname, which defaults to /hlfs/home.  Lookups within that
     directory are handled by hlfsd, which uses the password map to determine
     how to resolve the lookup.  The directory will be created if it doesn't
     already exist.  The symbolic link will be to the accessing user's home
     directory, with subdir appended to it.  If not specified, subdir defaults
     to .hlfsdir.  This directory will also be created if it does not already
     exist.

     A SIGHUP will flush the internal caches, and reload the password map.  It
     will also close and reopen the log file, to enable the original log file
     to be removed or rotated.	A SIGUSR1 will cause it to dump its internal
     table of user IDs and home directories to the file
     /usr/tmp/hlfsd.dump.XXXXXX.

OPTIONS

     -a alt_dir
	     Alternate directory.  The name of the directory to which the sym-
	     bolic link returned by hlfsd will point, if it cannot access the
	     home directory of the user.  This defaults to /var/hlfs.  This
	     directory will be created	if it doesn't exist.  It is expected
	     that either users will read these files, or the system adminis-
	     trators will run a script to resend this ``lost mail'' to its
	     owner.

     -c cache-interval
	     Caching interval.	hlfsd will cache the validity of home directo-
	     ries for this interval, in seconds.  Entries which have been ver-
	     ified within the last cache-interval seconds will not be verified
	     again, since the operation could be expensive, and the entries
	     are most likely still valid.  After the interval has expired,
	     hlfsd will re-verify the validity of the user's home directory,
	     and reset the cache time-counter.	The default value for
	     cache-interval is 300 seconds (5 minutes).

     -f      Force fast startup.  This option tells hlfsd to skip startup-time
	     consistency checks such as existence of mount directory, alter-
	     nate spool directory, symlink to be hidden under the mount direc-
	     tory, their permissions and validity.

     -g group
     -i reload-interval
	     Map-reloading interval.  Each reload-interval seconds, hlfsd will
	     reload the password map.  hlfsd needs the password map for the
	     UIDs and home directory pathnames.  hlfsd schedules a SIGALRM to
	     reload the password maps.	A SIGHUP sent to hlfsd will force it
	     to reload the maps immediately.   The default value for
	     reload-interval is 900 seconds (15 minutes).

     -l logfile
	     Specify a log file to which hlfsd will record events.  If logfile
	     is the string syslog then the log messages will be sent to the
	     system log daemon by syslog(3), using the LOG_DAEMON facility.
	     This is also the default.

     -n      No verify.  hlfsd will not verify the validity of the symbolic
	     link it will be returning, or that the user's home directory con-
	     tains sufficient disk-space for spooling.	This can speed up
	     hlfsd at the cost of possibly returning symbolic links to home
	     directories which are not currently accessible or are full.  By
	     default, hlfsd validates the symbolic-link in the background.
	     The -n option overrides the meaning of the -c option, since no
	     caching is necessary.

     -o mount-options
	     Mount options.  Mount options which hlfsd will use to mount
	     itself on top of dirname.	By default, mount-options is set to
	     "ro".  If the system supports symbolic-link caching, default
	     options are set to "ro,nocache".

     -p      Prints PID.  Outputs the process-id of hlfsd to standard output
	     where it can be saved into a file.

     -v      Version.  Displays version information to standard error.

     -x log-options
	     Specify run-time logging options.	The options are a comma sepa-
	     rated list chosen from: fatal, error, user, warn, info, map,
	     stats, all.

     -C      Force hlfsd to run on systems that cannot turn off the NFS
	     attribute-cache.  Use of this option on those systems is discour-
	     aged, as it may result in loss or mis-delivery of mail.  The
	     option is ignored on systems that can turn off the attribute-
	     cache.

     -D log-options
	     Select from a variety of debugging options.  Prefixing an option
	     with the string "no" reverses the effect of that option.  Options
	     are cumulative.  The most useful option is all.  Since this
	     option is only used for debugging other options are not docu-
	     mented here.  A fuller description is available in the program
	     source.  A SIGUSR1 sent to hlfsd will cause it to dump its inter-
	     nal password map to the file /usr/tmp/hlfsd.dump.XXXXXX.

     -P password-file
	     Read the user-name, user-id, and home directory information from
	     the file password-file.  Normally, hlfsd will use getpwent(3) to
	     read the password database.  This option allows you to override

     /hlfs
	   directory under which hlfsd mounts itself and manages the symbolic
	   link home.

     .hlfsdir
	   default sub-directory in the user's home directory, to which the
	   home symbolic link returned by hlfsd points.

     /var/hlfs
	   directory to which home symbolic link returned by hlfsd points if
	   it is unable to verify the that user's home directory is accessi-
	   ble.

SEE ALSO

     mail(1), getgrent(3), getpwent(3), mtab(5), passwd(5), amd(8), cron(8),
     mount(8), sendmail(8), umount(8)

     "HLFSD: Delivering Email to Your $HOME", Proc. LISA-VII, The 7th Usenix
     System Administration Conference, November 1993.

AUTHORS

     Erez Zadok <ezk@cs.columbia.edu>, Department of Computer Science,
     Columbia University, New York, USA.

     Alexander Dupuy <dupuy@smarts.com>, System Management ARTS, White Plains,
     New York, USA.

HISTORY

     The hlfsd utility appeared in FreeBSD 3.0.

FreeBSD 5.4		      September 14, 1993		   FreeBSD 5.4

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