Qubes OS Troubleshooting: Solving Common Display, Networking, and Update Problems.

My Screen Went Black… Again. Sound Familiar?

I’ve lost count of how many times I’ve booted Qubes, sipped my coffee, and then—bam—blank screen. No cursor, no TTY, just me and my reflection in a glossy 27-inch rectangle of frustration.

The first time it happened, I panicked. Like full-on “re-install everything” panic. Good news? I now have a notebook that’s half spicy flex-grow memes and half handwritten command logs.

Here’s the real takeaway: display wonkiness, flaky Wi-Fi, and failed updates aren’t Qubes picking on you. They’re side effects of running a hyper-locked-down OS on ordinary hardware.

So let’s walk through the mess, step by step, without sounding like a manual that’s been run through Google Translate six times.

Fix 1—Dead or Flickering Screen

Symptom grab-bag: black screen on boot, weirdly huge fonts, cursor teleporting, external monitor decides it’s now a disco strobe.

1. Check what Xen thinks about your GPU

   xl dmesg | grep -i gpu

   Seeing “no VGA devices” or a long NVIDIA rant? That’s your cue.

2. Give your AppVM more memory

   qvm-prefs work mem 2048          # baseline
   qvm-prefs work maxmem 4096   # breathing room

   Engineers testing 3D CAD hot-rods pushed this to 6144. For most folks, 2–4 GB is the sweet spot.

3. Ditch the binary blob drivers
   I swapped the proprietary NVIDIA blob for nouveau on my backup laptop—and for the first time the external monitor came on without the HDMI-cable dance.

   sudo dnf remove \*nvidia\*
   sudo dnf install xorg-x11-drv-nouveau
   qvm-shutdown guivm
   qvm-start guivm

   P.S. Make a snapshot of your template first. Trust me on this one.

Fix 2—No Internets, Even Though Your Wi-Fi Icon Is Smiling

I once spent six hours chasing DNS errors only to discover the cat had stepped on a USB-C dongle and half-killed the Wi-Fi card assignment.

• Is sys-net running?

  qvm-check sys-net
  qvm-start sys-net  # if it’s down

• See what PCI devices you actually own

  qvm-pci ls | grep -i wlan

  If the line ends in “monolithic dom0” it’s still stuck in dom0.

• Restart the network pieces

  qvm-run -a sys-net 'sudo systemctl restart NetworkManager'

  Sounds overkill. Takes 8 seconds. Works more often than I care to admit.

Pro move: next time you’re online, install nmcli-dmenu inside sys-net. One Alt+Space later you’re toggling Wi-Fi networks without opening a single terminal.

Fix 3—“Updates Available” Stuck at 0 %

Updates dangling at 0 % usually mean one of three things: disk full, laggy mirror, or a GPG key rotated and forgot to text you.

1. Free up headroom in dom0

   sudo dnf autoremove
   sudo package-cleanup --oldkernels --count=2

2. Purge the cache

   sudo qubes-dom0-update clean all
   sudo rm -rf /var/cache/dnf/dom0-*

3. Update one template at a time

   qvm-run -a fedora-38 'sudo dnf update -y'

   I cap it at one round per lunch break. Less panic, more caffeine.

Kit That Rarely Breaks

Happiness list straight from the hardware-forum trenches:

• Laptop: ThinkPad T-series ≥ 2018 (Intel graphics play nicer than NVIDIA).
• Wi-Fi: Intel AX200/AX210 cards. Broadcom still hates open-source drivers.
• SSD: 256 GB or bigger; 50 k IOPS keeps template snapshots from crawling.

Check Qubes HCL before clicking “buy.”

Weekly Ritual I Actually Follow

I keep a sticky note on my monitor that reads:

1. Monday: review dom0’s journal for new warnings
2. Wednesday: backup templates with qvm-backup to an external SSD
3. Friday: update one “tier-1” template (say, fedora-38-work), then reboot on the weekend

Takes fifteen minutes before the coffee hits. Has saved my data at least four times.

When It’s Bigger Than You

Still stuck?

• Post your xl dmesg snippet and exact model number in the Qubes Forum. The maintainer team usually replies faster than my pizza guy.

Remember—each fix you log becomes a breadcrumb for the next person (and your future self) who wakes up to a scolding blank screen. That, in my book, is community-powered security.