Linux

48555 readers

1360 users here now

From Wikipedia, the free encyclopedia

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

Rules

Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise.
No misinformation
No NSFW content
No hate speech, bigotry, etc

Related Communities

Community icon by Alpár-Etele Méder, licensed under CC BY 3.0

founded 5 years ago

MODERATORS

[email protected]

How to troubleshoot broken ssh if you do GPU passthrough? (sh.itjust.works)

submitted 1 day ago by [email protected] to c/[email protected]

22 comments fedilink hide all child comments

This hasn't happened to me yet but I was just thinking about it. Let's say you have a server with an iGPU, and you use GPU passthrough to let VMs use the iGPU. And then one day the host's ssh server breaks, maybe you did something stupid or there was a bad update. Are you fucked? How could you possibly recover, with no display and no SSH? The only thing I can think of is setting up serial access for emergencies like this, but I rarely hear about serial access nowadays so I wonder if there's some other solution here.

you are viewing a single comment's thread
view the rest of the comments

[–] [email protected] 3 points 1 day ago (2 children)

I passthrough a GPU (no iGPU on this mobo).
It only hijacks the GPU when I start the VM, for which I haven't configured autostart.
Before the VM is started it's showing the host prompt. It doesn't return to the prompt if the VM is shutdown or crashed, but a reboot would, hence not autostarting that VM.
If it got borked too much, putting a temporary GPU might be easier.

Also, don't break your ssh.
Pretty easy with PKI auth.

[–] [email protected] 1 points 1 day ago (1 children)

It only hijacks the GPU when I start the VM

How did you do this? All the tutorials I read hijack the GPU at startup. Do you have to manually detach the GPU from the host before assigning it to the VM?

[–] [email protected] 1 points 15 hours ago

Interesting.
I'm not doing anything special that wasn't in one of the popular tutorials and I thought that's how it was supposed to work, although it might very well be a "bug" how it behaves right now.

I don't know enough about this, but the drivers are blacklisted on the host at boot, yet the console is still displayed through the GPU's HDMI at that time which might depend on the specific GPU (a vega64 in my case).

The host doesn't have a graphical desktop environment, just the shell.