Network problems while running VirtualBox

[Peter Ross]

Hi all,

I have a problem with the network while running VirtualBox.

As soon as I _run_ a VirtualBox I am not able to copy large files  
(e.g. virtual disks or ZFS snapshots) using ssh/scp to another machine.

The ssh crashes with "Write failed: Cannot allocate memory"

thrown by a write(2) in /usr/src/crypto/openssh/roaming_common.c (in  
function roaming_write). It returns the ENOMEM (an error it should  
never return, according to the mainpage;-)

It is immediately working when I stop the VirtualBox, even if the  
VirtualBox kernel modules are still loaded.

I also "replaced" the VirtualBox load with lookbusy occuping the 2GB  
of memory the VirtualBox usually uses (to emulate the memory  
footprint) but it still works.

I experienced the problem with VirtualBox 3.2 first but the upgrade to  
VirtualBox 4.0.8 and the base system recently did not help.

> uname -a
FreeBSD DellT410one.vv.fda 8.2-STABLE FreeBSD 8.2-STABLE #1: Thu Jun  
30 17:07:18 EST 2011  
root at DellT410one.vv.fda:/usr/obj/usr/src/sys/GENERIC  amd64

I discussed it on the -stable mailinglist before, as the link to  
VirtualBox wasn't obvious to me at first. Scott Sipe had the same  
experience, he started the thread:

http://lists.freebsd.org/pipermail/freebsd-stable/2011-July/063172.html

He comes to the same conclusion:

http://lists.freebsd.org/pipermail/freebsd-stable/2011-July/063234.html

> This is it -- I'm seeing the exact same thing.
>
> Scp dies reliably with VirtualBox running. Quit VirtualBox and I was able to
> scp about 30 large files with no errors. Once I started VirtualBox an
> in-progress scp died within seconds.
>
> Ditto that the Kernel modules merely being loaded don't seem to make a
> difference, it's VirtualBox actually running.
>
> virtualbox-ose-3.2.12_1

Some technical details related to my machine:
http://lists.freebsd.org/pipermail/freebsd-stable/2011-July/063221.html

to Scott's here: http://www.cap-press.com/misc/

A similar problem was reported by Mahlon E. Smith in September 2010:

http://lists.freebsd.org/pipermail/freebsd-stable/2010-September/058708.html

I became aware of it because there was the same bce(4) card involved  
but that may be a red herring. Scott's is using em(4).

At the moment it is a real showstopper for running VirtualBox/FreeBSD  
production because I cannot backup VirtualBoxes. Mahlon gave up on it  
and uses Citrix by now (but is still keen to have this solved).

Any idea what causes the problem? I am happy to gather information,  
applying patches etc. if it helps.

Thanks for any help
Peter