I've been migrating user home directories from one machine to another machine recently. In doing so I've come across the age old problem of users having too much junk, old user directories that need to be backed up for future reference and so on.

Instead of using tar like I normally would for most things, I chose to use dar. dar gives me the possibility of being able extract a single file without needing to stream through the entire archive.

To archive a user's home directory this is what I run

dar -c user -R / -g home/user -v

I guess rtfm and check man pages to see what the above options mean. Note I also have this in my .darrc

    #########################
    #           #
    #   Shared options pro  #
    #    DAR archiver   #
    #           #
    #########################

# Jakub Holy, 25.4.2005
# This file: /etc/darrc
# Note: If the user has her $HOME/.darrc, this file is ignored => it must be included with the option -B /etc/darrc to dar

###
### Files that shall not be compressed (because they're already)
###
# archives (Note: .tar is archive, but not compressed => do compress it).
-Z "*.bz2" -Z "*.deb" -Z "*.gz" -Z "*.Z" -Z "*.zip" -Z "*.rar" -Z "*.tbz2" -Z "*.tgz" -Z "*.jar" -Z "*.ear" -Z "*.war"
-Z "*.BZ2" -Z "*.DEB" -Z "*.GZ" -Z "*.Z" -Z "*.ZIP" -Z "*.RAR" -Z "*.TBZ2" -Z "*.TGZ" -Z "*.JAR" -Z "*.EAR" -Z "*.WAR"
# media - images
-Z "*.gif" -Z "*.jpeg" -Z "*.jpg" -Z "*.png" 
-Z "*.GIF" -Z "*.PNG" -Z "*.JPEG" -Z "*.JPG"
# media - audio
-Z "*.ogg" -Z "*.mp3"
-Z "*.OGG" -Z "*.MP3"
# media - video
-Z "*.avi" -Z "*.mov" -Z "*.mp4" -Z "*.mpg"
-Z "*.AVI" -Z "*.MOV" -Z "*.MP4" -Z "*.MPG"
# documents - compressed formats
-Z "*.pdf" -Z "*.swf" -Z "*.sxw"
-Z "*.PDF" -Z "*.SWF" -Z "*.SXW"
# strange formats, binaries and other hard to compress (empirical)
-Z "*.gpg" -Z "*.rnd" -Z "*.scm" -Z "*.svgz" -Z "*.vlt" -Z "*.zargo" -Z "*.wings" -Z "*.xpi" -Z "*.chm"
-Z "*.GPG" -Z "*.RND" -Z "*.SCM" -Z "*.SVGZ" -Z "*.VLT" -Z "*.ZARGO" -Z "*.WINGS" -Z "*.XPI" -Z "*.CHM"
-Z "*.obj" -Z "*.tif" -Z "*.tiff"
-Z "*.OBJ" -Z "*.TIF" -Z "*.TIFF"

###
### Ignored files
###
-X "*~" -X "*.o"    
# *~ are backups, *.o are compiled unlinked files

### jt's custom options
# -m dont compress files less than this size in bytes
# -v verbose
# -s slice up in this size
# -y compress with bzip2
-m 256 
-v
-s 2000M
-y

Once the archive has been created, it's probably not a bad idea to test it, you can do so by doing

dar -t user --noconf