http://www.virtualbox.org/

http://download.virtualbox.org/virtualbox/4.2.6/VirtualBox-4.2.6-82870-Linux_amd64.run

<code>
sh VirtualBox-4.2.6-82870-Linux_amd64.run &&
rm /etc/rc.d/rc*/*vboxdrv /etc/rc.d/rc*/*vboxweb-service</code>

==== reinstalling the vboxdrv and vboxnetflt kernel modules ====
<code>
cd /opt/VirtualBox/src/vboxhost &&
make &&
make install</code>

==== mounting a vdi ====
I have a dynamically expanding virtual hard disk (vdi).\\ 
Extract the real data:
<code>
VBoxManage internalcommands converttoraw input.vdi output.raw
</code>
Get the offset:
<code>
sfdisk -luS output.raw
</code>
<code>
Disk output.raw: cannot get geometry

Disk output.raw: 1305 cylinders, 255 heads, 63 sectors/track
Units = sectors of 512 bytes, counting from 0

   Device Boot    Start       End   #sectors  Id  System
output.raw1   *        63  20948759   20948697   7  HPFS/NTFS
output.raw2             0         -          0   0  Empty
output.raw3             0         -          0   0  Empty
output.raw4             0         -          0   0  Empty
</code>
The offset is startsector * sectors size, in this case: 63 * 512 = 32256\\ 
I installed Windows XP to the virtual hard disk (vdi) , which uses NTFS as filesystem.
<code>
mount -t ntfs -o ro,noatime,noexec,loop,offset=32256 output.raw /mnt/some_mount_point
</code>