Mounting USB drive in 4.2.4

User Support
1

So I’m bad at doing backups, so it’s been a while since I tried…

After plugging in the USB drive, it refuses to appear in the sys-usb cube so I can point my backup at it.

I also cannot attach to a app-vm; error mentions something about a “qubes-app-linux-usb-proxy blob.”

In searching the forums, I see issues like this with 4.3, but not 4.2.4.

I am running an up to date 4.2.4, debian-12 based sys-usb dvm.

Appreciate any thoughts.

Thanks.

2

First, check whether there are any hardware issues by running this command in the sys-usb terminal:

lsusb

If nothing appears, it may indicate a hardware or controller issue.

If devices do appear and there is no hardware problem, then check the USB proxy package by running:

sudo apt list --installed | grep qubes

Look for qubes-app-linux-usb-proxy. If it is missing, install it using:

sudo apt install qubes-app-linux-usb-proxy

Then restart your sys-usb and plug the USB drive in again.

3

Thanks for the help!

Interesting results:

lsusb does show the device, so good there.

The file is not installed, but upon trying to install I get:

user@debian-12-custom:~$ sudo apt-get install qubes-app-linux-usb-proxy
Reading package lists… Done
Building dependency tree… Done
Reading state information… Done
E: Unable to locate package qubes-app-linux-usb-proxy

I checked the sources file, and the repository is being checked:

user@debian-12-custom:/etc/apt/sources.list.d$ sudo apt update
Hit:1 Index of /debian bookworm InRelease
Hit:3 Index of /debian-security bookworm-security InRelease
Get:4 Index of /debian bookworm-backports InRelease [59.4 kB]
Hit:6 Index of /deb/r4.2/vm/ bookworm InRelease
Hit:7 Index of /r4.2/vm/ bookworm InRelease

What am I missing?

Thanks!

4

I think it is better to remove the sys-usb qube and create it again.

First, please read the official documentation:

https://doc.qubes-os.org/en/latest/user/advanced-topics/usb-qubes.html

Removing sys-usb

  1. Shut down the USB qube.

  2. In Qubes Manager, right-click on the USB qube and select “Remove VM.”

  3. Open the file /etc/default/grub in dom0.

  4. Find the line(s) that begin with GRUB_CMDLINE_LINUX.

  5. If rd.qubes.hide_all_usb appears in those lines, remove it.

  6. Save and close the file.

  7. Run the following command in dom0:

sudo grub2-mkconfig -o /boot/grub2/grub.cfg
  1. Reboot the system.

Creating sys-usb again

Run in dom0:

sudo qubesctl state.sls qvm.sys-usb

Manual method:

  1. Read the PCI devices documentation and identify your USB controller.

  2. Create a new qube and name it sys-usb.

  3. Go to the qube settings → Devices tab.

  4. Move the USB controller from “Available” to “Selected”.

  5. Apply changes and restart the qube.

  6. Enable: “Start VM automatically on boot”