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...