[CentOS] Best way to duplicate a live Centos 5 server?

Fri Jun 8 16:33:09 UTC 2012
Emmanuel Noobadmin <centos.admin at gmail.com>

I've got a CentOS 5 server that I want to migrate over into a
virtualized instance.
The problem is I need to minimize downtime so was trying to figure out
a way to "live" clone the original.

Initially, I thought I could do this via exporting an iSCSI target
from the virtual host, create a MD raid 1 array on the C5 server, wait
for it to sync, then shutdown the physical server and switch to the
virtual one.

But after getting iSCSI working... I realize I could not create a md
device on a mounted disk. Unfortunately this old C5 wasn't setup with
md raid 1 originally so I can't just add a the iSCSI target as an
additional member for a triplicate.

So I remembered DRBD was supposed to be used for replication.

But after getting things set up, running the drbd-admin create-md
command gave me this scary warning it will destroy data on the disk.
Apparently because drbd writes meta data to the drive. So that appears
to be a no go too.

Am I missing something glaringly obvious here, or is the only way I'm
going be able to migrate is to shutdown the C5 server for a few hours
while duping the old drives? Would greatly appreciate any pointers how
best to do this.