I have a stand alone server running Arch 2009.08 x64 and it was configured via the 'Netinst' CD however during the time of the installation, the server had only one physical disk. I installed the system as follows: * /dev/sda1 = swap * /dev/sda2 = boot * /dev/sda3 = / * /dev/sda4 = /var Now I have since obtained identical drives on this system which show up as /dev/sdb and /dev/sdc. Both of the new drives are identical. I have the system running perfectly however I would like to create /dev/sdb and /dev/sdc in a mirror. I can use 'cfdisk' utility to create RAID partitions on the newly installed drives using the 'fd' code. Can I simply just use 'mdadm' utility to create a mirror after I create the partitions with out messing up my configured / working Arch Linux server? Code: mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sdb1 /dev/sdc1 The Wiki has a write up (which I have never been able to get working) on RAID / LVM but this appears to be configured during the installation of Arch which I have already done. Not to mention I have followed the Wiki guide dozens of times to no avail. I even gave up on trying to install the swap and root partitions on the RAID and just do /home and it still fails. Anyone know if I will run into any issues?