VM crash after KVMS switch

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HarryMan
Posts: 113
Joined: 15. Jan 2014, 13:54
Primary OS: Debian other
VBox Version: OSE Debian
Guest OSses: devuan, MX-Linux, others

VM crash after KVMS switch

Post by HarryMan »

No idea why/what caused this crash. I was working in this VM (same one I changed to USB 3 a few days ago to address viewtopic.php?f=7&t=104857, mentioning this in case it might be relevant) without any particular issues or problems. I switched to a different computer using a USB switchbox (KVMS) and worked on there for a while. When I switched back to the first PC, I expected to see the VM still running but it had aborted.

Other than these facts, I am not sure why it suddenly crashed. Attached is log.
 Edit: : The log file timestamp on the host seems to indicate that the last message was at Jan 4 19:33 (PST)
 Edit: : It happened again after a computer switch. This time, the host was unrecoverable. I shut down as much as I could cleanly and rebooted the whole host machine. Log is attached.

Out of curiosity, I changed the vm back to USB 2. So far, switching between the 2 PCs has not caused the VM to crash. 
 
Attachments
myvm-2022-01-04-23-57-04.log.gz
(24.96 KiB) Downloaded 7 times
myvm-2022-01-04-19-33-34.log.gz
(31.3 KiB) Downloaded 7 times
mpack
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Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
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Re: VM crash after KVMS switch

Post by mpack »

Both logs are truncated, either due to the abort or due to you grabbing the file while VirtualBox was still running.

As a separate suggestion, why not just launch the VM headless, and RDP to it? That way you don't need the KVM switch.

Your problem may be caused because it's a USB hosted KVM: so each switch implies a set of USB devices being unplugged and replugged. VirtualBox needs to do nasty things when that happens, and it may not expect them to happen in parallel.
HarryMan
Posts: 113
Joined: 15. Jan 2014, 13:54
Primary OS: Debian other
VBox Version: OSE Debian
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Re: VM crash after KVMS switch

Post by HarryMan »

mpack wrote:Both logs are truncated, either due to the abort or due to you grabbing the file while VirtualBox was still running.
I can assure you that vbox was NOT running when I copied the files. I've double-checked; these are the gzip'd logfiles as I saved them from the Log dialog box in the GUI. Perhaps this points to a part of the problem?
As a separate suggestion, why not just launch the VM headless, and RDP to it? That way you don't need the KVM switch.
I've done that at times. But there are also times when switching back and forth is necessary, such as when booting the other machine--it requires that the video card on that system syncs with the monitor. I do not seem to be able to do anything about that behavior.

But there are also other times, such as when RDP or SSH loses connectivity for whatever reason. The other box is a test box, and it is not unheard of for a test to fail, right? :D (No, there were no failures on the test box at the time of the crashes on the first box. I switched back to monitor something periodically.)
Your problem may be caused because it's a USB hosted KVM: so each switch implies a set of USB devices being unplugged and replugged. VirtualBox needs to do nasty things when that happens, and it may not expect them to happen in parallel.
I agree completely. In fact, I highly suspect that is exactly the cause of the crashing. After all, once I switch back to USB 2 in the VM in question, the crashing no longer occurs.

What you say after that concerns me greatly, though. It is hard for me to hear that virtualbox cannot handle this switching without getting nasty about it. A VM is supposed to behave very close to actual hardware, so this is very disappointing. Stranger yet, this does NOT happen when running under USB 2.

I conclude that USB 3 requires more nastiness than USB 2 when performing such switching.

Does Oracle have plans to fully support USB 3 in the future?

Also... the switchbox is not even attached to the VM. The functionality should be handled by the host. I hope that the traffic generated by the switchbox would never reach virtualbox's ears.
mpack
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Re: VM crash after KVMS switch

Post by mpack »

HarryMan wrote: Does Oracle have plans to fully support USB 3 in the future?
I have no idea what Oracle plans. If you want to hear from Oracle then you'd have to buy a support contract.

Meanwhile you could raise a bugtracker ticker about the KVM problem with USB3.
HarryMan
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Primary OS: Debian other
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Re: VM crash after KVMS switch

Post by HarryMan »

HarryMan
Posts: 113
Joined: 15. Jan 2014, 13:54
Primary OS: Debian other
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Guest OSses: devuan, MX-Linux, others

Re: VM crash after KVMS switch

Post by HarryMan »

I have a new KVMS now. I may re-attempt the experiment again with this new switchbox. This one does not support hotkey switching (which never really worked on the first one anyway) because they want to be able to support more configurations (which sounds like a good idea based on my own experience here).

Hopefully, this new switchbox will operate properly.
HarryMan
Posts: 113
Joined: 15. Jan 2014, 13:54
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Re: VM crash after KVMS switch

Post by HarryMan »

So far, so good... except that there was a crash one time (see viewtopic.php?f=3&t=105820) Note that I was running an older kernel there that did not support USB 3 yet. (That is coming soon; I'll update this then.)

So I am not sure this is really "solved" as such, although I would aver my new KVMS does appear to be more stable than my old KVMS. For one thing, it has no hot key switching, which seems to be a problem with these devices.

One other issue I have seen with this switch is that if it is connected to one of my PCs that is off, it can hang the switch (or so it appears). Once I disconnect it, my new KVMS seems happy enough and works faithfully. The mainboard on that PC is a bit old and does not seem to handle USB keyboard and mouse, at least not at boot.
HarryMan
Posts: 113
Joined: 15. Jan 2014, 13:54
Primary OS: Debian other
VBox Version: OSE Debian
Guest OSses: devuan, MX-Linux, others

Re: VM crash after KVMS switch

Post by HarryMan »

It's baaaaaack!

This time, virtualbox 6.1.40 with GA 6.1.40. What I notice is that the VM only crashes when I switch away and back with the KVMS if the VM is in full screen. This does not happen, it seems, when it is not in full screen mode.

Again, host and guest are Devuan Chimaera with all the latest upgrades. VBox Extension pack 6.1.40 is installed. I've rebooted the host but problem persists when VM is in full screen mode.

Another problem is that the VboxXPComIPCD daemon dies when launching the very first VM (from desktop link) upon reboot. However, it works just fine if I launch the first VM from VirtualBox GUI; then I can launch any VM from either the GUI or the desktop. I even re-created the desktop links from the GUI, but that has had no effect.

Oddly, even though this PC is configured almost the same as my other PC, the other PC does not experience this problem. Yes, something must be different, but the error messages I get do not immediately reveal the source of the problems.
Attachments
test-chimaera-2023-01-11-17-16-55.log.gz
Crashed VM Log
(23.75 KiB) Not downloaded yet
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