Honestly I'd not even use such one for filesystem backup. When I do a backup and what to have a posibility of ease restore I usually use the dump-tool. Example:
You want to backup all data on hda1 and use a compression level 9 for that (= maximum compression) then you'd do
dump -0 -z9 -f example.dump /dev/hda1
The location of the example.dump should not be on the same partition (example.dump should not be on hda1). It might be helpful at a later state to know about the partitions so maybe do a
df -alh > partitions
At the later state when you want to restore the dump, join the directory where you want to put the filesystem you dumped on (e. g. /var) and type
restore rf example.dump
If you have a RH rescue CD for instance you can boot up with that CD and have the dumps on a FTP-server (username can be anything but password has to be empty) and restore the whole server using FTP ...
I've restored a huge server (COMPLETELY) in 1 hour ... now that safes you some time in case of let's say if your box got hacked and binaries replaced with trojaned versions or something alike
Hope this helps