My sys-usb disappeared over a night (probably an update?)

thimbles_taxidermist · August 19, 2026, 2:49pm

I don’t know what is going on with dom0 or whatever the updates are doing but over a night after an update the sys-usb qube is no more.
My sys-usb has template a (disposable) sys-usb-dvm that is made from another template of debian-13-usb.
I even tried to make a new sys-usb, and when I started it throwed an error and then got deleted? removed? auto-disappeared.
Has anyone experienced something like that?
Solutions? what could be the issue? which info do you need from the OS etc?

disp7321 · August 19, 2026, 2:57pm

github.com/qubesos/qubes-issues

named disposable fails to start so hard it gets deleted

opened 03:02PM - 07 Aug 26 UTC

RandyTheOtter

C: core P: default diagnosed pr submitted affects-4.3

[How to file a helpful issue](https://www.qubes-os.org/doc/issue-tracking/) ###… Qubes OS release 4.3 ### Brief summary If a named disposable linux qube kernel panics during startup, it gets deleted from the system. Upon such failure, the qube never reports shutdown, and desktop launchers are preserved at first, but any attempt to interact with the qube (by running `qvm-ls qube`, for example) removes them as well. In my case kernel panics with message `not syncing: VFS: Unable to mount root fs on unknown-block(0,0)`, which should be early during boot (reported half a second in). I haven't tested other panic options or failures, like an actual qrexec timeout. I doesn't seem to work with AppVMs. I haven't tried other classes. ### Steps to reproduce 1. Obtain a panicky named disposable; I do it via currently failing nvidia driver build in a debian template: https://github.com/NVIDIA/open-gpu-kernel-modules/issues/1272 This should not be particularly card-specific, perhaps you could use it too. `virt_mode` and pci assignment are irrelevant - it fails similarly in `pvh` mode. 3. Try to start it 4. Try to find it ### Expected behavior ```console $ qvm-prefs disposable_template template panic $ qvm-start named_disposable Error: Start failed: internal error: linxenlight failed to create new domain 'named_disposable', see /var/log/libvirt/libxl/libxl-driver.log for details $ qvm-ls named_disposable named_disposable ``` ### Actual behavior Below is `pvh` version of the output. `hvm` returns bogus qrexec timeout. ```console $ qvm-prefs disposable_template template panic $ qvm-start named_disposable Error: Start failed: internal error: linxenlight failed to create new domain 'named_disposable', see /var/log/libvirt/libxl/libxl-driver.log for details $ qvm-ls named_disposable ... qvm-ls: error: no such domain: 'named_disposable' ``` ### Additional information As far as I can tell libxl driver log maybe nods toward this bug being tied to mount failure specifically: ``` 2026-08-06 14:26:58.017+0000: xc: panic: xg_dom_core.c:205: failed to open file '/var/lib/qubes/vm-kernels/pvgrub2-pvh/vmlinuz': No such file or directory: Internal error 2026-08-06 14:26:58.017+0000: libxl: libxl_dom.c:937:libxl__domain_firmware: xc_dom_kernel_file failed: No such file or directory 2026-08-06 14:26:58.017+0000: libxl: libxl_dom.c:1103:libxl__build_hvm: initializing domain firmware failed 2026-08-06 14:26:58.017+0000: libxl: libxl_create.c:1753:domcreate_rebuild_done: Domain 41:cannot (re-)build domain: -1 ```

thimbles_taxidermist · August 19, 2026, 4:04pm

thank you! so just waiting and praying, I should probably switch to non-disp

disp7321 · August 19, 2026, 5:30pm

You can still use named disposables if they won’t encounter any errors when you start them.

FranklyFlawless · August 20, 2026, 2:47am

sudo qubesctl --show-output state.apply qvm.sys-usb

Qubesquark · August 21, 2026, 7:47pm

After installing today’s updates on my desktop box, the usb mouse stopped working. After plugging and unplugging and a couple of reboots, it finally did work again. However the usb sound doesn’t work now. I also don’t have a listing for sys-usb in the system. Any ideas please?

Qubesquark · August 21, 2026, 8:58pm

Only partial success. I decided to bite the bullet and add a new sys-usb following the instructions in the Qubes Documentation under usb. I do now have a sys-usb but the sound from the speakers is very low. The level cannot be brought up using the System Settings - Volume Control - method. Have also tried connecting the usb speakers plug to various usb input jacks with no difference in volume. I have tried Analog-Stereo-Duplex and Analog-Stereo-Output in the volume Configuration settings there as well. No difference. This update today has really messed things up it seems.