As the OS is new enough. You could use vmware-converter. This is what I've used with good results to an esxi server. Once you have the vmdk you can move this to other virtual server software such as virtual box.

Other options available are clonezilla, or live cd with ssh and netcat.

Ideally you would want to migrate to a single virtual disk. Just so it's easier to manage in the future. I'm unsure of the best way to get this done. Sorry.

Andy

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