Is it possible to combine 2 virtual disks and add them to a VM?

[farfy]

I have 1 R530 server with a 17TB virtual disk, plus a Dell md3200i with a single 35TB disk. Both disks are in proxmox and I can add them to the VM, however I'm trying to combine them as one big disk. I was looking into mergerfs to do this (VM is running Ubuntu), however I thought it might make more sense to combine the disks at the host level instead of the VM level.

Is it possible to create a disk group of the 2 virtual drives in Proxmox so it appears as one single drive to the VM?

If so, is it possible of creating the disk group without losing existing data on one of the drives? It isn't catastrophic if not, I'd just prefer not to download 12TB all over again if it can be helped...

 

[Kingneutron]

You can do this concept with LVM, but not without losing the existing data. I don't recommend using LVM in VMs if you can at all avoid it; much more convenient to use separate virtual disks instead of partitions for easier resizing.

If you have ~52TB of data and no backup, you should arguably look into buying (or building) a NAS. And/or possibly tape backup.

Try thinking outside the box. My question is, why do you "need" 2 huge virtual disks combined into 1? You might be able to accomplish what you need with soft symlinks. More info is needed about your intended use case.

If the data involved weren't multiple-terabytes large, the "standard" thing to do is create 1 new virtual disk and copy everything over. But it sounds like you need more storage for that. If it's only actually 12TB then you might just want to buy a 20TB disk or similar, if budget allows.