Last weekend, I set out to repartition my computer. Since my root partition was only 7 GB, I figured that I would increase it at the expense of my home partition (which is substantially bigger, since it stores all of my data and personal settings). Since the partition editor I was using does not have support for moving ext3 partitions, it was necessary to delete my home partition and recreate it. Anticipating that something like this might happen, I had spent several hours creating a complete backup of everything using the Unix utility tar.
Probably because I am still used to using Windows (where every user is an administrative user, and it is difficult for administrative users to pretend to be other users), I used Knoppix to attempt to restore all 34 gigabytes of my data. The first time, Knoppix (in text-mode, to save resources) froze halfway through. The second time, I forgot to mount my home partition read-write (Knoppix mounts partitions read-only by default). The third time, I realized that tar in Knoppix was refusing to extract files after a certain limit (maybe 6 gigabytes or so). This was a problem, because tar was taking a ridiculously long time to parse my 34 gigabyte backup file, and then was only extracting the first couple hundred of files, most of which were non-essential.
In case the problem was the version of tar that came with Knoppix, I logged in to my computer as root and pretended (through su) to extract the files as my local user (to make sure the permissions of each extracted file was correct). Because a random page I found through Google suggested it, I used:
cat backup.tar | tar -xv
Not only was this faster than using tar by itself, but it was able to extract all of my files, including the 20 GB or so of music (FLAC takes up a lot of space) I have ripped from CDs.