I have a CentOS 4.2 system that was set up VERY quickly following the demise of its former life as a CentOS 3 server - you don't want the full story, but it had to be done quickly to get a company up and working following a slight disaster involving an electrician, a portable appliance safety tester and a pulled power cable - anyway, here's where I am at... Everything is running fine but I now want to mirror the root partition (/dev/hda3). I have read quite a few set of notes on the theory but since they contain conflicting advice I am hoping someone here can set me straight - here's what IO want to do: hda3 and hde3 become a mirrored pair (/dev/md0) and this is mounted at boot time as / Is it as simple as a quick mdadm command and then an edit of /etc/inittab?? If I try and use mdadm right now I get complaints that /dev/hda3 is busy (fair enough) so I guess I need to be in less than 'full steam ahead' mode to make the change - over to you.... Thanks