Xen Enterprise 5 to VMWare ESXi 3.5 Migration

So I decided to get off my multi year xen kick with a migration finale over to the free version of vmware 3.5i ESX. There were a few political reasons for this move, but the most important part of it was cost and upgrade path to maintain a commercial product as my primary virtualization platform.

A large supporting factor was the fact that Xen is not compatible with the Supermicro Blade set I purchased a few months back. This was a huge investment I made to consolidate space, have an inexpensive and quick upgrade path to scale/grow with. The blades can be easily found on VMware's HCL ;) Citrix was not very interested in moving into a position of support, so I got the thumbs down on compatibility from their team..

I started out by flashing the LSI MPT bios. Vmware went right on these babies with no fuss. Next I started testing vmware with a few low traffic virtual machines. VmWare held up well. I wasnt flattered, but just satisfied with it's performance. So to kick off the migration to vmware, I started with my windows domU's. The vmware conversion tool made this a breeze! I installed the package on every machine due to the fact I am too frugle to buy an enterprise license.. After the tool installed, I was able to click through the wizard and suck the machines right into my ESX Server! That was pretty swift, I must admit...

After the machines were fired up on the ESX server, I had to install the vmware tools, adjust some IP addresses and rename the adapters for easy admin. After the reboot, all the alerts from the monitoring system cleared and we were back in business. About 8 virtual servers were migrated this way, disks ranging in size from 39gb to 100gb. Actual time for the longest conversion was only 35 minutes or so over a gigabit copper switch.

Next I am faced with 4 CentOS 5.x linux servers left on this dom0. I tried a few different methods to seemlessly migrate this host to vmware, all of which failed. Tried methods include ghosting (ghost would not load network drivers on vmware host + lvm was lost during the process), completed backup via tar then relocation to the new machine, and rsync to rsync with both systems in rescue mode.

NOTE: To boot from CD on xen server enterprise 5 use the following command from the CLI: xe vm-param-set HVM-boot-policy="BIOS order" uuid=After you issue the command, you will be able to set the boot order in the management gui software.

When you want to boot back from the virtual hard drive device, issue the command, but set the boot-policy directive to "". You will still have to define the uuid of the DomU.

I finally gave up on a clone type movement and decided to install the new vm and just migrate the critical data over. This worked very well, and I did not experience any down time for this web server becuase I left the old data up long enough for DNS to propagate, then removed the old web server from the farm.