I have been an Ubuntu Desktop user for almost two months now, so let me update you a bit.
About a week ago, I made a HUGE mistake when running the command line as root (I can just imagine some of you grinning already). No, I was not using the rm command! That has to be the first line in every Linux book you read -- WARNING!!! Then an example of wiping out your system with the rm command.
The 'mistake' I made, was not actually done on purpose -- it was kind of a 'wrong place, wrong time' thing -- let me explain. I was in the middle of copying some files to a new, shared directory that I setup to share with my LAN. This is when I had to 'chown' (CHange OWNership) the copied files -- I started to type the command
sudo chown -R langroup:langroup /
when I was interrupted. Can you see it? The FULL command was going to be
sudo chown -R langroup:langroup /home/lan-shared
as I only wanted to change the ownership on that directory and it's recursive directories (hence the -R option). But I turned around, after my interruption, and hit the enter key without completing the command.
I still wasn't aware of what I did -- it took about 4 or 5 seconds before I looked at the screen and saw it. Then, I realized what I had done! I had, inadvertently, issued a command, as root (sudo) to change the ownership (chown) of directories and files, recursively (-R), to the 'langroup' user and group (langroup:langroup), starting from the ROOT directory (/). Obviously, this is NOT what I wanted. :(
I quickly escaped the command (Ctrl-c), but it was waaaaay too late. Almost every directory and file on my system was now owned by 'langroup' -- you can only imagine the havoc that wreaked.
It took quite a long time to get sorted out -- I actually gave up on trying to save the system, but I wanted my files! The short and sweet of the recovery process was to boot the LiveCD in another machine and look at the directory structure and, more importantly, the ownership of the directories/files. From there, boot the machine I was having problems with from the LiveCD and get into recovery mode (ie. the command line -- or 'shell'). There you are root and can start changing ownership to what they should be -- therein lies the time. Oh, my goal was simply to get network connectivity back so I could transfer my files. Or even get my CD writer back! Something to allow me to get my files. I ended up achieving network connectivity and was able to get my files.
I will now offer you a tip that would have saved my bacon, had I known it at the time. When installing Linux (any flavor) set yourself up a separate partition for your /home directory. Why? Simply because if you set it up in that manner, you save all your files to a separate partition on your hard drive. In the event of a serious problem, such as I have outlined above, you can simply reinstall the OS without touching (ie. without formatting) the /home partition. As an added bonus, you can install a newer version of the OS (say, for example, when Ubuntu Fiesty 7.x is released) as a clean install, and not an upgrade, if you so desire. The structure would be like so (keep in mind, this is for a single boot, Linux only machine -- do a Google search if you need dual boot instructions);
Example -- you have an 80G drive.
/ (root) ext3 -- 10G
/home ext3 -- 69G
/swap linux-swap -- 1G
10G is plenty for the OS, and the 1G swap can be altered to your needs (depending on the amount of memory you have, etc.), but is a good base. Assign the majority of your drive to your home directory, as this is where the majority of files will be stored. Now, if you ever have to reinstall, you can choose NOT to format the /home partition and your data will be intact upon completion of the install.
This problem actually worked out better for me, in the long run -- here's why;
I initially installed Ubuntu on a P3 machine, and not one of my better ones, simply because I was testing the OS and didn't know if I'd like it, or stick with it. I quickly found that I did like it, used it the most, and wished I had put it on a better machine. Part two of that is that I also wanted to install Beryl (a Linux Theme Manager -- all kinds of cool stuff that'll give any Vista user a run for their money!), but it just didn't like the older hardware (especially the ATI video card!) and wouldn't run.
Well, seeing that I now had to reinstall Ubuntu, now was the perfect time! Instead of reinstalling Ubuntu on that machine, I threw Window$ XP back on it as I still, unfortunately, need a Windows machine (no, I haven't tried 'Wine'... yet!). From there, I copied all the files over from my current XP machine and then installed Ubuntu on that machine -- a P4 3.2GHz dual core machine with 2G of ram, 2 x 200G SATA drives, yadda, yadda, yadda.
I'm happy to announce that Beryl installed without a hitch -- and man, IS IT SWEET! Do a search for 'Beryl' over at YouTube.com -- there are a bunch of videos there demonstrating Ubuntu & Beryl.
The moral to this post? The 'chown' command can be just as dangerous as the 'rm' command, if you're not careful! ;)