DESCRIPTION

     pdumpfs is a simple daily backup system written in Ruby (ruby(1)), which
     is similar to Plan9's dumpfs that preserves every daily snapshot.

     Back up your home directory with pdumpfs, and you can retrieve any past
     day's snapshot of any file.

     pdumpfs constructs each day's snapshot in the directory named YYYY/MM/DD
     under the destination directory.  All source files are copied to the
     snapshot directory for the first time, and on and after the second time,
     pdumpfs copies only updated or newly created files and stores unchanged
     files as hard links to the files of the previous day's snapshot to save
     disk space.

     The latest version of pdumpfs is always available at
     http://namazu.org/~satoru/pdumpfs/.

EXAMPLE

     To backup your home directory /home/yourname to /backup, run the follow-
     ing command.

           pdumpfs /home/yourname /backup >/backup/log 2>/backup/error-log

     On and after the second day, it is a good idea to invoke the backup com-
     mand with cron(8) daemon.  Adding the following line to your crontab file
     allows you to back up your home directory at 5 a.m. everyday.

           00 05 * * * pdumpfs /home/yourname /backup >/backup/log
           2>/backup/error-log

     If the backup system works well, you can retrieve any given day's file
     with a file name like /backup/2001/02/19/yourname/...

LIMITATION

     -   pdumpfs can only handle normal files, directories, and symbolic
         links.

     -   pdumpfs may not work on systems other than UNIX because pdumpfs uti-
         lizes hard links.

     -   pdumpfs is not suited for a directory containing large files which
         are updated frequently.

     -   If more than 31 day absence occurs, incremental backup would not be
         performed.  So, back up your files on a daily basis.

     -   With pdumpfs, you can safely remove unnecessary files because the
         past files can be retrieved at any time.  However, you must not rely
         too much on pdumpfs.  It may have serious bugs.

TIPS

               chflags -R schg /backup

         These commands will keep you from accidentally removing your backup
         files with rm -rf.

AUTHOR

     pdumpfs and the HTML document were written by Satoru Takabayashi
     <satoru@namazu.org>.

     This manual page was translated from the HTML document by Hiroyuki
     Shimada <shimaden@din.or.jp>, and reformatted by Akinori MUSHA
     <knu@iDaemons.org>.

SEE ALSO

     chattr(1), chflags(1), crontab(5), cron(8)

                               November 25, 2001