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Backing Up Files with dump

The dump command was historically one of the most commonly used tools for performing backups on UNIX systems. This command traces its history back to the early days of UNIX and thus is a standard part of nearly every version of UNIX. Likewise, the dump package is included in Fedora and Red Hat Enterprise Linux. If it was not installed by default when you first set up your Linux system, you can install it from the dump RPM file located on the Fedora installation DVD.

Note: The dump and restore commands, while widely used for many years, are not considered to be particularly reliable or robust backup and restore tools these days. Also, they can be used only on ext2 and ext3 file system types and it is safest to use dump and restore on unmounted file systems. Descriptions of those tools are included here to support those with legacy backup media and automated scripts that still use those commands.
The dump package actually consists of several commands. You can read online man pages for more information about them. Table 4-5 provides a short description of the programs.
Table 4-5: Programs in the dump Package

Creating backup with dump

When making a file system backup using the dump command, you must supply parameters specifying the dump level, the backup media, and the file system to back up. You can also supply optional parameters to specify the size of the backup media, the method for requesting the next tape, and the recording of file system dump times and status. The first parameter to dump is always a list of single-letter option codes. This is followed by a space-separated list of any arguments needed by those options. The arguments appear in the same order as the options that require them. The final parameter is always the file system or directory being backed up.
# dump options arguments filesystem

Linux Administration

dump backup command

The -u option will update the file /etc/dumpdates, which will record dump information for future use. This command performs a full backup of the /home file system onto the tape device nrst1 and record the dump information in /etc/dumpdates as specified by the -u option.

This use of the -u option performs an incremental update of all files that have been changed or added since the last backup of level 4 or lower, as recorded in the
/etc/dumpates
file.