VBox: VMs randomly fail with assertion: Expression: cbPreRead == 0

[Yuri]

On 08/24/2013 13:54, Yuri wrote:
> Here is the message:
> 00:10:44.838619 !!Assertion Failed!!
> 00:10:44.838619 Expression: cbPreRead == 0
> 00:10:44.838621 Location  : 
> /usr/ports/emulators/virtualbox-ose/work/VirtualBox-4.2.16/src/VBox/Storage/VD.cpp(2272) 
> int vdWriteHelperOptimized(VBOXHDD*, VDIMAGE*, VDIMAGE*, uint64_t, 
> size_t, size_t, size_t, size_t, const void*, void*, unsigned int)
>
> Gues OS: FreeBSD 9.1 (both i386 and amd64)


Here is how to repeat: in a new VM with an empty disk install system 
from 9.1 iso. Update /usr/src and rebuild world+kernel, install gnome2 
from ports. Get this error eventually.
I only observed it with FreeBSD guests, not with linux or windows guests.

Currently, version 4.2.16 isn't usable with FreeBSD guests for this 
reason. I downgraded to 4.2.14 and it died with assertion the same way. 
Not sure if this is because VM created on 4.2.16 was reused.
Some previous version (not sure which exactly) was very stable and I 
used it with BSD guests for a long time.

Yuri