Booting Debian off phisical HDD in VirtualBox on WinXP host
While working in windows on dualboot system, it's handy to have access to linux system, installed on the same phisical machine. It'spossible by booting linux off the phicical hard drive in a virtual machine. I use VirtualBox with raw disk image for this:
First, look how VirtualBox sees the phisical partition:
$ VBoxManage.exe internalcommands listpartitions -rawdisk '\\.\PhysicalDrive0' Number Type StartCHS EndCHS Size (MiB) Start (Sect) 1 0x07 0 /1 /1 1023/254/63 30718 63 2 0x07 1023/254/63 1023/254/63 149997 62910540 3 0x83 1023/254/63 1023/254/63 286 370106368 5 0x83 1023/254/63 1023/254/63 57472 370694144
Here we see partitions 1,2 as WinXP C: and D: drives, partition 3 as /boot, and partition 5 as LVM. Now we create raw disk image with only needed linux partitions 3,5 (we don't want to mess with windows disks used by live windows host).
$ VBoxManage.exe internalcommands createrawvmdk -rawdisk '\\.\PhysicalDrive0' -partitions 3,5 -filename raw-disk.vmdk RAW host disk access VMDK file raw-disk.vmdk created successfully.
There are 2 resulting files:
raw-disk.vmdk - text file virtual disk description
raw-disk-pt.vmdk - MBR and partition data from phisical disk
$ file -b raw-disk.vmdk ASCII text $ file -b raw-disk-pt.vmdk | sed 's/\; /\;\n/g' x86 boot sector; partition 1: ID=0x7, active, starthead 1, startsector 63, 62910477 sectors; partition 2: ID=0x7, starthead 254, startsector 62910540, 307194930 sectors; partition 3: ID=0x83, active, starthead 254, startsector 370106368, 585728 sectors; partition 4: ID=0x5, starthead 254, startsector 370694142, 117702658 sectors, code offset 0x1e
Now in VirtualBox we create a standard linux Debian virtual machine. In System -> Processor tab, enable PAE/NX. Add raw-disk.vmdk as SATA disk. Enable second network adapter, and set it attached to Host-only Adapter (it's going to be used for network communication between guest and host, so, configure it via /etc/network/interfaces on guest later).
We can boot it now, but we will be facing a TrueCrypt boot loader, sitting in the MBR:
$ hexdump -C -n 32 raw-disk-pt.vmdk 00000000 ea 1e 7c 00 00 20 54 72 75 65 43 72 79 70 74 20 |..|.. TrueCrypt | 00000010 42 6f 6f 74 20 4c 6f 61 64 65 72 0d 0a 00 fa 33 |Boot Loader....3| 00000020
So, pressing escape needed to get to the grub2 in PBR of /boot partition. To eleminate TrueCrypt boot loader when booting in virtual machine, it's possible to play around with replacing bootstrap code in raw-disk-pt.vmdk image (like described here), but more simple shortcut would be to create a grub4dos boot floppy image (script and instructions here), and chainload grub2 on /boot partition via it, by modifying menu.lst on floppy root:
timeout 0 # chainload grub2 from /boot partition (/dev/sda3) title grub2 kernel (hd0,2)/grub/core.img
and adding resulting floppy image to our virtual machine, as primary boot device.