Comments on: Taming Windows 7 in a VirtualBox VM Using Raw Disk Access

By: ningbao

ningbao — Tue, 16 Feb 2010 19:15:33 +0000

Is there a typo here?
You said:
Set the VM to mount the DVD drive and put in your Vista DVD. Start the VM.

What does a Vista DVD (instead of a Windows 7 DVD? ) have to do with this?

Or, I missed something here?

By: javatexan

javatexan — Tue, 16 Feb 2010 16:07:38 +0000

I can't get mine to work...I have Ubuntu 9.10/VB 3.1.4r57640. I added myself to the disk group and vboxusers group. I have the same setup as you do, a dualboot with windows 7 enterprise and ubuntu9.10. Ubuntu9.10 is my host os. I have all on sda with sda1-win7 100MB part sda2-win7 87G. I get all the way to booting the system and trying the recovery stuff. The recovery claims that it fails and I get these errors. http://imagebin.ca/view/vyhycT.html and http://imagebin.ca/view/yvoZZd.html. Someone on #vbox said that it may mean that win7 doesn't know how to access the vmdk. At this point I am very lost and not sure what to try next. Thanks.

By: Sape

Sape — Wed, 03 Feb 2010 12:32:19 +0000

Note: if you use VBox 3.1.2, then the regression is gone again, no need to downgrade.
Note: if you use the version which is not fully open source but still freely available (and has USB support as well), then you do not need the insecure chmod-ing above either. You only need to add your user to the vboxusers and disk group in /etc/group (line looks like: vboxusers:x:121:sape). In my system (Ubuntu Karmic) ls -l /dev/sda* shows:
brw-rw—- 1 root disk 8, 0 2010-02-03 15:54 /dev/sda
brw-rw—- 1 root disk 8, 1 2010-02-03 15:54 /dev/sda1
brw-rw—- 1 root disk 8, 2 2010-02-03 16:30 /dev/sda2
brw-rw—- 1 root disk 8, 3 2010-02-03 15:54 /dev/sda3
brw-rw—- 1 root disk 8, 5 2010-02-03 15:54 /dev/sda5
brw-rw—- 1 root disk 8, 6 2010-02-03 15:54 /dev/sda6

By: John

John — Wed, 03 Feb 2010 00:37:45 +0000

Thanks for reply Rajat – I look forward to reading the write up.

By: Rajat Arya

Rajat Arya — Wed, 06 Jan 2010 22:21:10 +0000

John – Sorry I have not had a chance to update these steps with the added
instructions in the comments – I hope to get time this coming weekend to get
the dual-boot to work without the repair step. In terms of the downgraded
VirtualBox – you should be able to use 3.0.12 and forward – the fix is
included in that version.

Hope this helps and thanks for reading.

Rajat

By: John

John — Fri, 01 Jan 2010 20:04:43 +0000

Hi Rajat,

Firstly thanks for the post. I am researching this process and your guide/post is the best I have found. I too want to have ubuntu as the host and Windows as the guest. At present I have just windows 7 installed, and I am on the verge of repartitioning the hard disk and installing Ubuntu. That is one to ponder eh? Well, I have a couple of questions for you:

You dont mention your system specs. I have a 32 bit dual core @ 2.0 laptop with 4 gig of ram. How much did you put aside in Virtualbox for the 7 VM to get comparable performance to when 7 runs in standalone mode?

I see a few folks have made comments about having to run the 7 repair app on standalone or vm restart. Have you overcome this? D Parker's comments looks great - but I'll need to reread it a few times to follow it. Lastly, how easy was it to downgrade virtualbox?

Thanks in advance,
John

By: Sape

Sape — Tue, 15 Dec 2009 04:22:09 +0000

Same here. I am not bothered by the native boot self-healing itself, but that would be nice the other way around too. Is it maybe possible to install a recovery console to the same partition too, as it worked with XP?

By: KM

KM — Mon, 14 Dec 2009 22:34:05 +0000

I used this technique. However, when ever I switch from VBox to Native boot (or the reverse) I must do a repair. In the case of native it does the repair on boot, and then does a second boot. In the case of VBox it requires the DVD image to do the repair and reboot. Either way its painful.

Is there a way to avoid the repair on each switch?

By: fazan

fazan — Sun, 13 Dec 2009 03:14:15 +0000

I tried following your suggested steps but I'm getting a BSOD when I try to run the Windows partition, even after repairing the Windows 7 install from the DVD. Here's my partition layout according to VBoxManage:

VirtualBox Command Line Management Interface Version 3.0.8
(C) 2005-2009 Sun Microsystems, Inc.
All rights reserved.

Number Type StartCHS EndCHS Size (MiB) Start (Sect)
1 0x07 0 /32 /33 162 /162/2 1200 2048
2 0x07 162 /162/3 1023/239/63 64913 2459648
5 0x83 1023/239/63 1023/239/63 44053 135414783
6 0x82 1023/239/63 1023/239/63 1926 225635823
3 0x07 1023/239/63 1023/239/63 10000 229586944

and according to fdisk:

Disk /dev/sda: 128.0 GB, 128035676160 bytes
255 heads, 63 sectors/track, 15566 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x02f2e53c

Device Boot Start End Blocks Id System
/dev/sda1 * 1 154 1228800 7 HPFS/NTFS
Partition 1 does not end on cylinder boundary.
/dev/sda2 154 8429 66471262 7 HPFS/NTFS
Partition 2 does not end on cylinder boundary.
/dev/sda3 14292 15566 10240000 7 HPFS/NTFS
Partition 3 does not end on cylinder boundary.
/dev/sda4 8430 14291 47083680 5 Extended
Partition 4 does not end on cylinder boundary.
/dev/sda5 8430 14046 45110488+ 83 Linux
/dev/sda6 14046 14291 1973128+ 82 Linux swap / Solaris

Does it make a difference that my partitions aren't aligned on cylinder boundaries? I've read that this isn't ideal for other performance reasons (it's a 128GB SSD), but I didn't think the partition alignment would affect the ability to load the raw W7 partition.

I also tried DParker's suggestion of making the Linux partition accessible to VBox, and I did indeed get the grub menu to show up, but selecting the Windows partition caused an immediate crash.

Any advice?

By: Sape

Sape — Sat, 05 Dec 2009 22:38:34 +0000

Yes, it did work for me like described here!