PDUMPFS(8)

NAME
pdumpfs - A daily backup system similar to Plan9's dumpfs.

SYNOPSIS
pdumpfs src-dir dest-dir [dest-basename]

DESCRIPTION
pdumpfs is a simple daily backup system similar to Plan9's dumpfs which preserves every daily snapshot. pdumpfs is written in Ruby (ruby(1)). You can access the past snapshots at any time for retrieving a certain day's file. Backup your home directory with pdumpfs! pdumpfs constructs the snapshot YYYY/MM/DD in the destination directory. All source files are copied to the snapshot directory for the first time. 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 for saving a disk space. The latest version of pdumpfs is available at http://namazu.org/~satoru/pdumpfs/.

EXAMPLE
To backup your home directory /home/yourname to /backup, run the following 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 command with cron(8) daemon. The following setting allows you to backup your home directory every 5 a.m.
  00 05 * * * pdumpfs /home/yourname /backup \
  >/backup/log 2>/backup/error-log If the backup system works well, you can retrieve a certain day's file with a file name like /backup/2001/02/19/yourname/...

LIMITATION
- pdumpfs can handle only normal files, directories, and
  symbolic links.
- pdumpfs may not work on systems other than UNIX because
  pdumpfs utilizes hard links.
- pdumpfs is not suited for a directory containing large
  files which update frequently.
- If more than 31 days absence occurs, incremental backup
  would not be performed. So, backup your files everyday.
- With pdumpfs, you can easily remove unnecessary files
  because the past files can be retrieved at any time.
  However please do not put too much confidence in
pdumpfs. pdumpfs may have serious bugs.

TIPS
- If files are increased by 10 MB everyday, about 4 GB
  disk space is consumed by one year. It is not too much,
  considering the recent evolution of computer resources.
- Backup your files to a physically separated device.
- With linux, files can be immutable with chattr(1)
  command. To make all files in /backup immutable, run
chattr -R +i /backup with the root privilege. chattr
  command keep you from doing rm -rf backup files by
  accident.

AUTHOR
This manual page was translated the HTML document by Hiroyuki Shimada <shimaden@din.or.jp> which is written by Satoru Takabayashi <satoru@namazu.org> for the Debian GNU/Linux system (but may be used by others).

.SEE ALSO
cron(8), crontab(5), chattr(1)