External USB disk restarts VM


Jun 2, 2021

I have a number of VMs and in some of them I have connected an external USB disk for backup reasons. All USB disks are new and all are USB 3.0.

The following issue started happenig after the last changes in USB connection settings in VMs where it now recognizes automatically if a disk is USB 2.0 or 3.0 etc. and it has happened a lot of times since then. Before that I used USB external disks for years without any issues.

When I try to replace USB disks with a fressh set, i first remove USB disks by ejecting them from the tasklbar. After that I rarely see anymore the message that says taht It is safe to remove the disk no matter how long I wait, 1 minute or 5 minutes.

And If I remove the disks forcibly the VM restarts on the spot (Windows Server 2019 VMs).

This is happening to all of my VMs with USB external disks.

Do you have any idea why this is happening?

Best regards

Noone has encountered this issue with external USB disks?

Today I had the same issue with all my VMs.

Best regards

I use 2.5'' USB3.0 external HDDs for VMs backup and almost every time I change the sets I unplug them first from Windows and then from the cables.

When i unplug from the cables, even when I do not see them In Windows as attached, the VMs crash and restart.

This started happening after the latest changes in Proxmox USB where it auto senses if a HDD is USB2.0 or 3.0.


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