id	summary	reporter	owner	description	type	status	component	version	resolution	keywords	cc	guest	host
16660	VM window freezes and process keeps running after manual savestate	Philip Seeger		"There are several vms on this host, usually running in full screen mode. One vm has been experiencing this issue where the full screen vm window freezes, usually after the vm has been running for one or more days. I haven't noticed that issue with other vms, however, most other vms don't run for weeks.

When it happens, the vm window is not updated anymore. It doesn't show the vm anymore. Instead, it shows whatever was there on the screen earlier. If there was another window above the frozen window and that other window is closed, it's still shown in the frozen vm window. If I switch workspaces back and forth, when I switch back to the workspace with the frozen vm window, the vm window (which is in full screen mode) shows the previous workspace.
For that reason, a screenshot wouldn't be helpful, as it would simply show whatever else was on the screen before the frozen vm window was activated.

This affects the vm window, i.e., the window that shows up when you start a vm in the VirtualBox gui. The affected vm itself is still running and can be accessed via ssh.

It is possible to suspend the vm using ""vboxmanage controlvm [NAME] savestate"", but the frozen vm window won't go away. It visually looks as if nothing had changed.
The vm process keeps running after the vm is suspended:
{{{
user     985 27147 64 00:02 ?        08:10:26 /usr/lib/virtualbox/VirtualBox --comment Fedora-1 --startvm 5c908c7b-bf32-4965-be4d-a11f5abdbf04 --no-startvm-errormsgbox
user    7016     1  0 Apr04 ?        00:38:56 /usr/lib/virtualbox/VBoxXPCOMIPCD
user   27123     1  0 Apr10 ?        00:22:27 /usr/lib/virtualbox/VirtualBox
user   27147     1  0 Apr10 ?        00:47:51 /usr/lib/virtualbox/VBoxSVC --auto-shutdown
}}}

If this process (985 in this example) is killed, the frozen window disappears and VirtualBox marks the vm as ""Aborted"". The saved state is lost.
I usually reset the vm to its last healthy state and start it again, which works fine every time. Until the vm window freezes again a few days later.

It's not clear what causes these freezes. I understand that this makes it very difficult to debug this, but I'm hoping this bug report helps someone else out there who is experiencing the same behavior.

Looking at the log (attached), it seems like two log entries are missing. These entries can be found at the end of the log files of other vms that were also suspended (without freeze):
{{{
12:07:58.276482 GUI: UIMediumEnumerator: Medium-enumeration finished!
12:07:58.551772 GUI: Passing request to close Runtime UI from machine-logic to UI session.
}}}




"	defect	new	other	VirtualBox 5.1.18		freeze window process		Linux	Linux