[arch-general] Post Install for RAID Configuration?

[Carlos Williams]

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?