After the FreeBSD VM crash, file system in VM got rolled back to some old previous state causing data loss

[Sergey Slobodyanyuk]

>
> On 08/07/2013 01:56, Wojciech Puchar wrote:
> >
> > not possible in FreeBSD with UFS.
> >
> > but if you run virtualbox under linux i cannot say much...
>
> This happened with FreeBSD guest with UFS (journaled soft-updates) and
> FreeBSD host.
> What is out of normal, it rolled back for many hours (~20).
>
> Yuri
>
> Could be you are using *Immutable images *as type of disk for guest VM

   1.

   *Immutable images.* When an image is switched to "immutable" mode, a
   differencing image is created as well. As with snapshots, the parent image
   then becomes read-only, and the differencing image receives all the write
   operations. Every time the virtual machine is started, all the immutable
   images which are attached to it have their respective differencing image
   thrown away, effectively resetting the virtual machine's virtual disk with
   every restart.

 http://www.virtualbox.org/manual/ch05.html

//BR, Sergey