From: Les Mikesell <lesmikesell at gmail.com> Subject: Re: [CentOS] Best way to duplicate a live Centos 5 server? To: CentOS mailing list <centos at centos.org> On Fri, Jun 8, 2012 at 12:04 PM, Scott Silva <ssilva at sgvwater.com> wrote: >> 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... An interesting variation on this is to use 'ReaR' to back up and restore the machine, essentially cloning it but give the copy a different IP address as you bring it up. Then when the clone is close to ready to take over, shut down your apps for the time it takes a final rsync to fix up the differences (in the data areas only - avoid /etc/, (etc.), then switch the IP. ReaR is in active development now and is very usable. It is a set of shell scripts designed to run live backups that are capable of restoring to bare metal. It makes a new boot iso with tools from the running system to reconstruct the filesystem (including lvm/raid, etc.) and restore on top of that. Several backup methods are supported but tar to an nfs location is probably the easiest to set up. With a small amount of extra work you can tweak the filesystem layout, etc. if you don't want an exact clone. With hardware differences you might need to tweak modules and build a new initrd, too. ReaR is packaged in EPEL as rear. ReaR has suddenly become very interesting to me, probably explaining why it utterly fails to work properly (for me).I'm using 1.13 to pull a USB-based recovery image, but there's an error in the backup/NETFS/default/50_make_backup.sh script that doesn't mount the USB device after the mkrecovery step, so subsequent tar fails on write to the non-existent mountpoint. I fixed that, but on recovery it fails to mount the necessary directories on the restore drive as well, so "rear recover" quickly bombs out. Is anyone having any success actually using ReaR on CentOS 6.x? - csawyer