The PrintScreen key and usability of screenshots

User Support General
1

I had a problem in a dispVM connected to some web server, so I wanted to contact support, showing them some screenshots. Using QubesOS 4.2 with today’s updates.

First thing I noticed was that the screenshot function of Firefox was not available in Debian 12, so I used the PrintScreen key. That created a screenshot, but in Dom0!

Next thing I noticed was that Dom0 has no context menu in the file manager like “Move to VM…”, so I wondered how to get the screenshots into the dispVM.

I had attached (and mounted) a USB stick to Vault. Interestingly Dom0 offered to send the screenshot files to the USB stick. If that worked I guess it would have corrupted the filesystem.
So I unmounted the stick in Vault, mounted it in Dom0 and copied the files there.

When I tried to attach the stick to the dispVM (after unmounting it in Dom0) I realized that it says “attaching …”, and I did not get any error message, but the device was never attached to the VM (verified with lsblk). Actually I could not attach the stick to any VM until I unplugged it an re-plugged it!

So I wonder:

  1. Is the failure to reattach partitioned USB sticks known already?
  2. How is the user expected to make a screenshot of a VM window and use that in the VM?
  3. Does it make sense to have screenshots be saved in Dom0?
2

qvm-copy-to-vm myvm screenshot.png

You may want to copy to an non networked vm to crop and strip any metadata.

3

see this topic: QubesOS Screenshot Clipboard Solution - #7 by bkida

4
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look in documentation:

To attach your USB stick, attach it via “USB Devices” rather than “Data (block) Devices.”
If the stick doesn’t appear in your file manager, open a terminal inside the VM and mount it manually:

sudo mount /dev/xvdi /mnt

This will mount the USB stick directly at /mnt.
Note: Never mount the key to dom0, That could pose security issues if your USB key is corrupted.

Install xfce4-screenshooter in the template of your DispVM, then in a terminal, launch xfce4-screenshooter in DispVM’s terminal.

Sure because your keyboard is attach to dom0.

Edit: oups i didn’t see the answers! lol

6

I can highly recommend this:

I am using it with a global keybinding and it works pretty well.

1 Like
7

i didn’t know it :slight_smile:

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If you use alt + prtsc the screenshot if only of the active window, not the entire dom0 desktop.

You will still have to use qvm-copy-to-vm, from the command line, to copy the screenshot to a different qube.

2 Likes
9

wow! another think i didn’t know :open_mouth: thanks a lot @renehoj :smiley:
So simple in fact! lol

1 Like