12.4.2. Restoring files with tar

The --extract (-x) option for tar extracts files:

|

# **tar --extract --same-permissions 
--verbose --file 
/dev/fd0H1440**
usr/src/
usr/src/linux
usr/src/linux-1.2.10-includes/
usr/src/linux-1.2.10-includes/include/
usr/src/linux-1.2.10-includes/include/linux/
usr/src/linux-1.2.10-includes/include/linux/hdreg.h
usr/src/linux-1.2.10-includes/include/linux/kernel.h
...
#

</font> | | --- |

You also extract only specific files or directories (which includes all their files and subdirectories) by naming on the command line:

|

# **tar xpvf /dev/fd0H1440 
usr/src/linux-1.2.10-includes/include/linux/hdreg.h**
usr/src/linux-1.2.10-includes/include/linux/hdreg.h
#

</font> | | --- |

Use the --list (-t) option, if you just want to see what files are on a backup volume:

|

# **tar --list --file 
/dev/fd0H1440**
usr/src/
usr/src/linux
usr/src/linux-1.2.10-includes/
usr/src/linux-1.2.10-includes/include/
usr/src/linux-1.2.10-includes/include/linux/
usr/src/linux-1.2.10-includes/include/linux/hdreg.h
usr/src/linux-1.2.10-includes/include/linux/kernel.h
...
#

</font> | | --- |

Note that tar always reads the backup volume sequentially, so for large volumes it is rather slow. It is not possible, however, to use random access database techniques when using a tape drive or some other sequential medium.

tar doesn't handle deleted files properly. If you need to restore a filesystem from a full and an incremental backup, and you have deleted a file between the two backups, it will exist again after you have done the restore. This can be a big problem, if the file has sensitive data that should no longer be available.