Hi,
Miikka Salminen <miikka.salminen@gmail.com> (2017-01-30):
> Using VirtualBox 5.1.6 on a Windows 7 host, I created a virtual
> machine with the described above specifications, and inserted the
> Debian Stretch RC1 netinst .iso file as a CD.
>
> I tried both the graphical and the text mode installer - the result
> was same in both.
>
> I selected the default en_us options except for Finnish keyboard
> layout and Finland as the physical location. In the disk partitioning
> part I selected the guided LVM option, and from there, all the default
> options.
>
> For the installable software I only selected the SSH server and the
> base system tools (and unselected the desktop environment).
>
> For the GRUB installation I selected the /sda option from the two
> available options: Manual and /sda
>
> The installation hangs at 66% "Installing GRUB boot loader" with the
> text Running "update-grub"...
I suppose this is what I've just reported against os-prober:
https://bugs.debian.org/853277
If you have your VM handy right now, check whether there's a dmsetup
create process around:
ps | grep 'dmsetup create'
KiBi.