10 UNIX Command Line Mistakes

Anyone who has never made a mistake has never tried anything new. --
Albert Einstein.
Here are a few mistakes that I made while working at UNIX prompt. Some mistakes caused me a good amount of downtime. Most of these mistakes are from my early days as a UNIX admin.
userdel Command
The file /etc/deluser.conf was configured to remove the home directory (it was done by previous sys admin and it was my first day at work) and mail spool of the user to be removed. I just wanted to remove the user account and I end up deleting everything (note -r was activated via deluser.conf):
userdel foo
Rebooted Solaris Box
On Linux killall command kill processes by name (killall httpd). On Solaris it kill all active processes. As root I killed all process, this was our main Oracle db box:
killall process-name
Destroyed named.conf
I wanted to append a new zone to /var/named/chroot/etc/named.conf file., but end up running:
./mkzone example.com > /var/named/chroot/etc/named.conf
Destroyed Working Backups with Tar and Rsync (personal backups)
I had only one backup copy of my QT project and I just wanted to get a directory called functions. I end up deleting entire backup (note -c switch instead of -x):
cd /mnt/bacupusbharddisk
tar -zcvf project.tar.gz functions
I had no backup. Similarly I end up running rsync command and deleted all new files by overwriting files from backup set (now I