Disk passthrough to KVM - Unknown partition type on another machine

mrjack711

Member
Jun 17, 2018
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Hi,

I've got 3 disks currently passed through to a VM using the instructions here:
Passthrough Physical Disk to Virtual Machine (VM) - Proxmox VE

I created 1 partition per disk, each formatted as ext4 using fdisk/mkfs.ext4 from within the VM and this has been working fine for a while.

I'm now trying to move those disks to a physical machine running ubuntu.
The disks show up in fdisk, but whenever I try to do anything with the partitions (mount/fsck etc) i get the following error:
"Bad magic number in super-block while trying to open /dev/..."
I've tried this in 2 different physical machines and get the same error.

If i move the disks back to the proxmox host and fire up the VM they work fine.

Is this expected behaviour after partitioning the disks and formatting within the VM itself?
Is there anything i can do to make them available on other machines?

My hardware is:
Dell PowerEdge R420
PERC H310 mini controller
Disks are WD Green 4TB
 
Last edited:
Is this expected behaviour after partitioning the disks and formatting within the VM itself?
I dont think so. It is a while back that I did what you try to achieve but I had no such issues.
In which mode is the H310 running? Is it working as an HBA?
 
I'm not 100% sure. I haven't flashed the card from its default firmware and the disks show as Non-RAID in iDrac:
1611958831930.png

I will take a look through the bios tomorrow and see if I can find anything different.
 
So I've had a look through the BIOS and the disks show as physical non-RAID disks.
There are 0 virtual disks configured.

When I have them plugged into another machine and run fdisk, they show up with a a Linux Partition of the correct size.
If i go into GParted, they show up as Unknown partitions.
 

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