Apply VMware snapshot files to arbitrary block devices

For minimal-downtime inter-machine migration, rsync is really the gold standard. You pre-sync everything while the service is still up, then take down the service and run rsync again to copy just the changes.

That works great for a filesystem, but what about when you want to synchronise an entire VM’s block devices? What about when that VM is a VMware VM, and you’re trying to escape from VMware? You need vmdksync.

The purpose of vmdksync is to allow you to transfer a base image while the VM is still running, then shutdown the VM, copy the snapshot file, and apply it to the block device on the new VM server, and start the machine up. This can result in downtimes of less than 90 seconds (as opposed to the hours it can take to copy a large block device in it’s entireity).

Sound useful? Head on over to the git repo and download it today.

Full documentation is provided in the README, and further background is available in the announcement blog post.

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