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

Fri Jun 8 17:04:48 UTC 2012
Scott Silva <ssilva at sgvwater.com>

on 6/8/2012 9:33 AM Emmanuel Noobadmin spake the following:
> 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.
You could always rsync the old server to the new one... a few runs will get
99% of the files, and a quick run after the shutdown can get the rest... Have
a tar file ready of the needed config changes ready and untar it and start up
the new system...