FreeBSD 13 on bhyve freezes under load

[Michael Gmelin]

On Mon, 3 May 2021 11:14:45 +0200
Christian Stærk <xi at borderworlds.dk> wrote:

> Hello,
> 
> I recently upgraded one of my bhyve guests to FreeBSD 13.0-RELEASE.
> The host is running 12.2-RELEASE-p4.
> 
> The guest in question is used for building packages with poudriere
> and is always the first one to get upgraded to new releases.
> 
> The guest freezes consistently every time poudriere tries to build
> the thunderbird package. Although it is not a complete freeze. It
> responds to ping and programs like top and systat continue updating.
> However, all I/O operations seem to hang.
> 
> systat looks like this when it happens: 
> https://borderworlds.dk/~xi/FreeBSD%2013%20frozen.png 
> <https://borderworlds.dk/~xi/FreeBSD%2013%20frozen.png>
> 
> What is the best way to debug this?

Sharing top output might help (memory/swap and ZFS arc usage). Also,
make sure you're not low on diskspace (these are the two most common
issues I encountered with hanging bhyve VMs - out of non-virtual memory
and out of diskspace of the host machine filesystem).

Some basic info on the host and your VM configuration might also help
others to reproduce the problem.

-m

-- 
Michael Gmelin