Problems with storage drive passthrough and backup


New Member
Jun 30, 2023
I'm trying to run either a VM or LCX container using Debian which will host some file storage server software, on Disk A. I want all the files that will be served on Disk B. I am able to make a new storage drive in Proxmox using this Disk B and then have the LCX container use Disk B to store files. However, when I make backups, it backs up the whole Disk B drive to Disk A. Disk B will have many more files than Disk A can store, so I just want to back up the server, not the files it serves. Second problem is that if I delete the LCX container, all the files served will also be deleted.

I want the files on Disk B to remain untouched when I make a backup of the server or if I delete the server, and I want these files to remain on Disk B so that if I make a new VM/LCX I can start serving those files again.

I was able to sort of do this with a VM and followed the guide for "disk passthrough". The files on Disk B remained unharmed after deleting the VM. However, when backing up the VM, the files were also backed up with it.

So my questions:
1. Does disk passthrough only work with VMs? I saw something about LCX disk passthrough, but it looked janky and too complicated.
2. Is disk passthrough the only way to have files be untouched on the disk when deleting the VM/LCX that is using it? Making a new storage pool from Disk B in Proxmox and then assigning to to the VM/LCX doesn't work for this purpose, right? At least that's what I see from my testing.
3. Is it possible to make a backup up the VM/LCX (located on Disk A) without also backing up all the files from Disk B? Or should I disconnect Disk B every time I need to make a backup?

I'm a newb, but I'm learning.
1 the disk passthrough equivalent for containers is a bind mount
2. the only reliable one, yes
3. you can always configure per disk/mountpoint whether to include it in the backup or not


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