Setting udev permission for raw host disk access by virtualbox machine.

To allow raw host disk access by guest machine on VirtualBox the user must have read-write permission to all partitions which are to be accessed. You can do this by something like
but executing it every time you need to boot virtual machine is annoying. You may want to set the permissions at boot time.
In modern kernels (since 2.6) you can use the udev rules for setting default permissions to selected devices. I created a file /etc/udev/rules.d/60-whatever.rules with a following rule:
This sets the permission for everyone to read-write /dev/sda7 and /dev/sda8.

That's all I needed.