If you need to restore the system using the tarball, there are several ways to do it. If you have the tarball on a networked PC, you could boot to a live CD (knoppix is great) and restore it. To do this you would need to:
1. Boot live CD. When using Knoppix it would be preferable to use runlevel 2: "knoppix26 2" at the prompt would boot knoppix with the 2.6 kernel in runlevel 2
2. Format the partition that needs to be restored. ex: mkfs.reiserfs /dev/hda2
3. Make a directory for A. The network share, and B. The local hard drive partition to restore
4. Mount the Network drive and local partition to restore:
smbmount //192.168.1.2/path /mnt/network -o username=username
mount /dev/hda2 /mnt/harddrive
5. cd /mnt/harddrive
6. tar -xzvf /mnt/network/backup.tar.gz
7. cd / ;umount /dev/hda2 ;reboot
Note: 1. Be careful that your partitioning scheme allows you to do this, if you have a different partition for /usr, /home, etc you will need to tweak it a little bit. 2. Depending on your partitioning scheme, you may need to restore the MBR with lilo... /sbin/lilo
There are many conditions to worry about when using this method, therefore you may not want to do this if you have sensitive data on your system unless you are very farmilliar with the process.
I have used Symantec Ghost with Reiserfs 3.6, but I do not know if it works with other filesystems.