VirtualBox/ヒントとテクニック

メインの記事は VirtualBox を参照。

VirtualBox の仮想マシンを他のハイパーバイザーにインポート・エクスポート

他のハイパーバイザーで作成した仮想マシンを VirtualBox にインポートしたり、VirtualBox の仮想マシンを他のハイパーバイザーにエクスポートしたい場合、以下のセクションを読んでください。

additions の削除

Guest additions はほとんどのハイパーバイザーで利用することができます: VirtualBox には Guest Additions がありますが、VMware には VMware Tools が、Parallels には Parallels Tools が存在します。これらの追加コンポーネントはゲストのオペレーティングシステムをインストールした後に、仮想マシンの中にインストールするように作られています。ゲストのオペレーティングシステムのパフォーマンスやユーザビリティを向上させるためのデバイスドライバーやシステムアプリケーションから成ります [1]。

仮想マシンに additions をインストールしていた場合、先にアンインストールしてください。他のハイパーバイザーのドライバーを使用したままですと、ゲストの挙動がおかしくなったり、クラッシュしたり、あるいは全く起動しなくなったりする可能性があります (特に Windows ファミリーの場合)。

適切な仮想ディスクフォーマットの使用

This step will depend on the ability to convert the virtual disk image directly or not.

自動化ツール

Some companies provide tools which offer the ability to create virtual machines from a Windows or GNU/Linux operating system located either in a virtual machine or even in a native installation. With such a product, you do not need to apply this and the following steps and can stop reading here.

• Parallels Transporter which is non free, is a product from Parallels Inc. This solution basically consists in an piece of software called agent that will be installed in the guest you want to import/convert. Then, Parallels Transporter, which only works on OS X, will create a virtual machine from that agent which is contacted either by USB or Ethernet network.
• VMware vCenter Converter which is free upon registration on the VMware webiste, works nearly the same way as Parallels Transporter, but the piece of software that will gather the data to create the virtual machine only works on a Windows platform.

手動変換

First, familiarize yourself with the formats supported by VirtualBox and those supported by third-party hypervisors.

• Importing or exporting a virtual machine from/to a VMware solution is not a problem at all if you use the VMDK or OVF disk format, otherwise converting VMDK to VDI and VDI to VMDK is possible and the aforementioned VMware vCenter Converter tool is available.

• Importing or exporting from/to QEMU is not a problem neither: some QEMU formats are supported directly by VirtualBox and conversion between QCOW2 to VDI and VDI to QCOW2 is still available if needed.

• Importing or exporting from/to Parallels hypervisor is the hardest way: Parallels does only support its own HDD format (even the standard and portable OVF format is not supported!).

• To export your virtual machine to Parallels, you will need to use the Parallels Transporter tool described above.
• To import your virtual machine to VirtualBox, you will need to use the VMware vCenter Converter described above to convert the VM to the VMware format first. Then, apply the solution to migrate from VMware.

ハイパーバイザーの VM 設定を作成

Each hypervisor have their own virtual machine configuration file: .vbox for VirtualBox, .vmx for VMware, a config.pvs file located in the virtual machine bundle (.pvm file), etc. You will have thus to recreate a new virtual machine in your new destination hypervisor and specify its hardware configuration as close as possible as your initial virtual machine.

Pay a close attention to the firmware interface (BIOS or UEFI) used to install the guest operating system. While an option is available to choose between these 2 interfaces on VirtualBox and on Parallels solutions, on VMware, you will have to add manually the following line to your .vmx file.

ArchLinux_vm.vmx

firmware = "efi"

Finally, ask your hypervisor to use the existing virtual disk you have converted and launch the virtual machine.

ヒント: Similarly, in VMware products, you can replace the location of the current virtual disk location by adapting the .vmdk file location in your .vmx configuration file.

仮想マシンの起動管理

サービスを使って仮想マシンを起動

Find hereafter the implementation details of a systemd service that will be used to consider a virtual machine as a service.

/etc/systemd/system/vboxvmservice@.service

[Unit]
Description=VBox Virtual Machine %i Service
Requires=systemd-modules-load.service
After=systemd-modules-load.service

[Service]
User=username
Group=vboxusers
ExecStart=/usr/bin/VBoxHeadless -s %i
ExecStop=/usr/bin/VBoxManage controlvm %i savestate

[Install]
WantedBy=multi-user.target

ノート: Replace username with a user that is a member of the vboxusers group. Make sure the user chosen is the same user that will create/import virtual machines, otherwise the user will not see the VM appliances.

ノート: If you have multiple virtual machines managed by Systemd and they are not stopping properly, try to add RemainAfterExit=true and KillMode=none at the end of [Service] section.

vboxvmservice@your_virtual_machine_name systemd ユニットを有効化して、起動時に仮想マシンが実行されるようにしてください。直接起動したい場合、systemd ユニットを起動します。

VirtualBox 4.2 introduces a new way for UNIX-like systems to have virtual machines started automatically, other than using a systemd service.

キーボードショートカットを使って仮想マシンを起動

It can be useful to start virtual machines directly with a keyboard shortcut instead of using the VirtualBox interface (GUI or CLI). For that, you can simply define key bindings in .xbindkeysrc. Please refer to Xbindkeys for more details.

Example, using the Fn key of a laptop with an unused battery key (F3 on the computer used in this example):

"VBoxManage startvm 'Windows 7'"
m:0x0 + c:244
XF86Battery

ノート: If you have a space in the name of your virtual machine, then enclose it with single apostrophes like made in the example just above.

仮想マシンで特定のデバイスを使う

USB ウェブカメラ/マイクロフォンを使う

ノート: 以下の作業をする前に VirtualBox 拡張パックをインストールする必要があります。

1. 仮想マシンを止め、ウェブカメラ/マイクロフォンが使われていないのを確認します。
2. メイン VirtualBox ウィンドウを立ち上げ Arch マシンの設定に行き、USB セクションを見ます。
3. "Enable USB Controller" を選択します。それから "Enable USB 2.0 (EHCI) Controller" を選択します。
4. "Add filter from device" ボタンをクリック ('+' アイコンとケーブル)。
5. リストから USB ウェブカメラ/マイクロフォンデバイスを選択する。
6. OK をクリックして VM を起動。

ノート: マイクロフォンが "Add filter from device" メニューに表示されない場合、(手順3で) USB 3.0 や 1.1 オプションを使ってみてください。

ウェブカメラや他の USB ドライブの認識

ノート: This will not do much if you are running a *NIX OS inside of your VM, as most do not have autodetection features.

If the device that you are looking for does not show up on any of the menus in the section above and you have tried all three USB controller options, boot up your VM three seperate times. Once using the USB 1.1 controller, another using the USB 2.0 controller, etc. Leave the VM running for at least 5 minutes after startup. Sometimes Windows will autodetect the device for you. Be sure you filter any devices that are not a keyboard or a mouse so they do not start up at boot. This ensures that Windows will detect the device at start-up.

ゲストサーバーにアクセス

To access Apache server on a Virtual Machine from the host machine only, simply execute the following lines on the host:

$ VBoxManage setextradata GuestName "VBoxInternal/Devices/pcnet/0/LUN#0/Config/Apache/HostPort" 8888
$ VBoxManage setextradata GuestName "VBoxInternal/Devices/pcnet/0/LUN#0/Config/Apache/GuestPort" 80
$ VBoxManage setextradata GuestName "VBoxInternal/Devices/pcnet/0/LUN#0/Config/Apache/Protocol" TCP

Where 8888 is the port the host should listen on and 80 is the port the VM will send Apache's signal on.

To use a port lower than 1024 on the host machine, changes need to be made to the firewall on that host machine. This can also be set up to work with SSH or any other services by changing "Apache" to the corresponding service and ports.

ノート: pcnet refers to the network card of the VM. If you use an Intel card in your VM settings, change pcnet to e1000.

To communicate between the VirtualBox guest and host using ssh, the server port must be forwarded under Settings > Network. When connecting from the client/host, connect to the IP address of the client/host machine, as opposed to the connection of the other machine. This is because the connection will be made over a virtual adapter.

Windows ゲストにおける D3D アクセラレーション

最近のバージョンの VirtualBox ではゲストにおける OpenGL のアクセラレーションをサポートしています。マシン設定のビデオメモリを設定するところの下にあるチェックボックスで有効にして、VirtualBox の Guest Addtions をインストールするだけです。ただし、ほとんどの Windows のゲームは (DirectX に含まれている) Direct3D を使っており、OpenGL は使用していません。したがってこの方法ではアクセラレーションが効きません。しかしながら、(d3d コールを OpenGL に変換する) Wine の d3d ライブラリを借用することで Windows ゲストにおける Direct3D のアクセラレーションを発揮させることができます。これらのライブラリは現在 VirtualBox の Guest Addtions ソフトウェアに含まれています。

上記のとおり OpenGL のアクセラレーションを有効にした後、ゲストをセーフモードで再起動してください (VirtualBox の画面が消えて Windows の画面が表示される前に F8 を押下)。そして、VirtualBox の Guest Additions をインストールして、インストール中に "Direct3D support" のチェックボックスをオンにしてください。通常モードで再起動すると Direct3D がアクセラレーションされるようになっているはずです。

ノート:

• This hack may or may not work for some games depending on what hardware checks they make and what parts of D3D they use.
• This was tested on Windows XP, 7 and 8.1. If method does not work on your Windows version please add data here.

USB キーと VirtualBox

When using VirtualBox on a USB key, for example to start an installed machine with an ISO image, you will manually have to create VDMKs from the existing drives. However, once the new VMDKs are saved and you move on to another machine, you may experience problems launching an appropriate machine again. To get rid of this issue, you can use the following script to launch VirtualBox. This script will clean up and unregister old VMDK files and it will create new, proper VMDKs for you:

#!/bin/bash

# Erase old VMDK entries
rm ~/.VirtualBox/*.vmdk

# Clean up VBox-Registry
sed -i '/sd/d' ~/.VirtualBox/VirtualBox.xml

# Remove old harddisks from existing machines
find ~/.VirtualBox/Machines -name \*.xml | while read file; do
  line=`grep -e "type\=\"HardDisk\"" -n $file | cut -d ':' -f 1`
  if [ -n "$line" ]; then
    sed -i ${line}d $file
    sed -i ${line}d $file
    sed -i ${line}d $file
  fi
  sed -i "/rg/d" $file
done

# Delete prev-files created by VirtualBox
find  ~/.VirtualBox/Machines -name \*-prev -exec rm '{}' \;

# Recreate VMDKs
ls -l /dev/disk/by-uuid | cut -d ' ' -f 9,11 | while read ln; do
  if [ -n "$ln" ]; then
    uuid=`echo "$ln" | cut -d ' ' -f 1`
    device=`echo "$ln" | cut -d ' ' -f 2 | cut -d '/' -f 3 | cut -b 1-3`

    # determine whether drive is mounted already
    checkstr1=`mount | grep $uuid`
    checkstr2=`mount | grep $device`
    checkstr3=`ls ~/.VirtualBox/*.vmdk | grep $device`
    if [[ -z "$checkstr1" && -z "$checkstr2" && -z "$checkstr3" ]]; then
      VBoxManage internalcommands createrawvmdk -filename ~/.VirtualBox/$device.vmdk -rawdisk /dev/$device -register
    fi
  fi
done

# Start VirtualBox
VirtualBox

Note that your user has to be added to the "disk" group to create VMDKs out of existing drives.

VirtualBox の中でネイティブの Arch Linux 環境を実行

If you have a dual boot system between Arch Linux and another operating system, it can become rapidly tedious to switch back and forth if you need to work in both. Also, by using virtual machines, you just have a tiny fragment of your computer power, which can cause issues when working on projects requiring performance.

This guide will let you reuse, in a virtual machine, your native Arch Linux installation when you are running your second operating system. This way, you keep the ability to run each operating system natively, but have the option to run your Arch Linux installation inside a virtual machine.

永続的な命名規則を使用していることを確認

ハードウェアの構成によっては、ハードドライブを表すデバイスファイルが Arch Linux 環境をネイティブに実行したり仮想マシンの中で実行したときと異なっている可能性があります。この問題は FakeRAID を使っている場合などに発生します。FakeRAID デバイスは GNU/Linux ディストリビューションをネイティブで実行している場合は /dev/mapper/ にマッピングされ、デバイスにアクセスすることができます。しかしながら、仮想マシンの中では、ホストのオペレーティングシステムのドライバーが FakeRAID を制御して抽象化するために、/dev/sdaX などのマッピングがされないことがあるのです。

この問題を解決するには、両方のシステムで共通する命名規則を使用する必要があります。UUID を使用することで問題は解決します。ブートローダーや fstab ファイルで UUID を使うようにしてください。詳しくは fstab や永続的なブロックデバイスの命名を参照。

警告:

• Make sure your host partition is only accessible in read only from your Arch Linux virtual machine, this will avoid risk of corruptions if you were to corrupt that host partition by writing on it due to lack of attention.
• You should NEVER allow VirtualBox to boot from the entry of your second operating system, which, as a reminder, is used as the host for this virtual machine! Take thus a special care especially if your default boot loader/boot manager entry is your other operating system. Give a more important timeout or put it below in the order of preferences.

mkinitcpio イメージが正しいことを確認

mkinitcpio の設定で block フックが使われていることを確認:

/etc/mkinitcpio.conf

[...]
HOOKS="base udev autodetect modconf block filesystems keyboard fsck"
[...]

block が存在しない場合、追加して initramfs を再生成してください:

# mkinitcpio -p linux

物理ドライブから起動するための VM 設定を作成

.vmdk ディスクイメージの作成

Now, we need to create a new virtual machine which will use a RAW disk as virtual drive, for that we will use a ~ 1Kio VMDK file which will be mapped to a physical disk. Unfortunately, VirtualBox does not have this option in the GUI, so we will have to use the console and use an internal command of VBoxManage.

Boot the host which will use the Arch Linux virtual machine. The command will need to be adapted according to the host you have.

On a GNU/Linux host

There is 3 ways to achieve this: login as root, changing the access right of the device with chmod, adding your user to the disk group. The latter way is the more elegant, let us proceed that way:

# gpasswd -a your_user disk

Apply the new group settings with:

$ newgrp

Now, you can use the command:

$ VBoxManage internalcommands createrawvmdk -filename /path/to/file.vmdk -rawdisk /dev/sdb -register

Adapt the above command to your need, especially the path and filename of the VMDK location and the raw disk location to map which contain your Arch Linux installation.

On a Windows host

Open a command prompt must be run as administrator.

ヒント: On Windows, open your start menu/start screen, type cmd, and type Ctrl+Shift+Enter, this is a shortcut to execute the selected program with admin rights.

On Windows, as the disk filename convention is different from UNIX, use this command to determine what drives you have in your Windows system and their location:

# wmic diskdrive get name,size,model

Model                               Name                Size
WDC WD40EZRX-00SPEB0 ATA Device     \\.\PHYSICALDRIVE1  4000783933440
KINGSTON SVP100S296G ATA Device     \\.\PHYSICALDRIVE0  96024821760
Hitachi HDT721010SLA360 ATA Device  \\.\PHYSICALDRIVE2  1000202273280
Innostor Ext. HDD USB Device        \\.\PHYSICALDRIVE3  1000202273280

In this example, as the Windows convention is \\.\PhysicalDriveX where X is a number from 0, \\.\PHYSICALDRIVE1 could be analogous to /dev/sdb from the Linux disk terminology.

To use the VBoxManage command on Windows, you can either, change the current directory to your VirtualBox installation folder first with cd C:\Program Files\Oracle\VirtualBox\

# .\VBoxManage.exe internalcommands createrawvmdk -filename C:\file.vmdk -rawdisk \\.\PHYSICALDRIVE1

or use the absolute path name:

# "C:\Program Files\Oracle\VirtualBox\VBoxManage.exe" internalcommands createrawvmdk -filename C:\file.vmdk -rawdisk \\.\PHYSICALDRIVE1

On another OS host

There are other limitations regarding the aforementioned command when used in other operating systems like OS X, please thus read carefully the manual page, if you are concerned.

VM 設定ファイルの作成

ノート:

• To make use of the VBoxManage command on Windows, you need to change the current directory to your VirtualBox installation folder first: cd C:\Program Files\Oracle\VirtualBox\.
• Windows makes use of backslashes instead of slashes, please replace all slashes / occurrences by backslashes \ in the commands that follow when you will use them.

After, we need to create a new machine (replace the VM_name to your convenience) and register it with VirtualBox.

$ VBoxManage createvm -name VM_name -register

Then, the newly raw disk needs to be attached to the machine. This will depend if your computer or actually the root of your native Arch Linux installation is on an IDE or a SATA controller.

If you need an IDE controller:

$ VBoxManage storagectl VM_name --name "IDE Controller" --add ide
$ VBoxManage storageattach VM_name --storagectl "IDE Controller" --port 0 --device 0 --type hdd --medium /path/to/file.vmdk

otherwise:

$ VBoxManage storagectl VM_name --name "SATA Controller" --add sata
$ VBoxManage storageattach VM_name --storagectl "SATA Controller" --port 0 --device 0 --type hdd --medium /path/to/file.vmdk

While you continue using the CLI, it is recommended to use the VirtualBox GUI, to personalise the virtual machine configuration. Indeed, you must specify its hardware configuration as close as possible as your native machine: turning on the 3D acceleration, increasing video memory, setting the network interface, etc.

Finally, you may want to seamlessly integrate your Arch Linux with your host operating system and allow copy pasting between both OSes. Please refer to #Install the Guest Additions^{[リンク切れ: セクションが存在しません]} for that, since this Arch Linux virtual machine is basically an Arch Linux guest.

警告: For Xorg to work in natively and in the virtual machine, since obviously it will be using different drivers, it is best if there is no /etc/X11/xorg.conf, so Xorg will pick up everything it needs on the fly. However, if you really do need your own Xorg configuration, maybe is it worth to set your default systemd target to multi-user.target with systemctl isolate graphical.target as root (more details at Systemd#Targets table and Systemd#Change current target). In that way, the graphical interface is disabled (i.e. Xorg is not launched) and after you logged in, you can startx} manually with a custom xorg.conf.

VirtualBox からネイティブの Arch Linux 環境をインストール

場合によってはネイティブの Arch Linux 環境をインストールするのが有用な場合があります: VirtualBox を使って raw ディスク にインストールすることができます。既存のオペレーティングシステムが Linux ベースの場合、代わりに既存の Linux からインストールを読んでください。

This scenario is very similar to #Run a native Arch Linux installation inside VirtualBox, but will follow those steps in a different order: start by #Create a raw disk .vmdk image, then #Create the VM configuration file.

Now, you should have a working VM configuration whose virtual VMDK disk is tied to a real disk. The installation process is exactly the same as the steps described in #Installation steps for Arch Linux guests^{[リンク切れ: セクションが存在しません]}, but #Make sure you have a persistent naming scheme and #Make sure your mkinitcpio image is correct.

警告:

• For BIOS systems and MBR disks, do not install a bootloader inside your virtual machine, this will not work since the MBR is not linked to the MBR of your real machine and your virtual disk is only mapped to a real partition without the MBR.
• For UEFI systems without CSM and GPT disks, the installation will not work at all since:

• the ESP partition is not mapped to your virtual disk and Arch Linux requires to have the Linux kernel on it to boot as an EFI application (see EFISTUB for details);
• and the efivars, if you are installing Arch Linux using the EFI mode brought by VirtualBox, are not the one of your real system: the bootmanager entries will hence not be registered.

• This is why, it is recommended to create your partitions in a native installation first, otherwize the partitions will not be taken into consideration in your MBR/GPT partition table.

インストールが完了したら、GNU/Linux のインストールメディア (Arch Linux のインストールメディアでもかまいませんしそうでなくでも問題ありません) を使ってコンピュータをネイティブに起動して、インストールした Arch Linux 環境に chroot してからブートローダーをインストール・設定してください。

ネイティブの Windows 環境を仮想マシンに移動

If you want to migrate an existing native Windows installation to a virtual machine which will be used with VirtualBox on GNU/Linux, this use case is for you. This section only covers native Windows installation using the MSDOS/Intel partition scheme. Your Windows installation must reside on the first MBR partition for this operation to success. Operation for other partitions are available but have been untested (see #Known limitations for details).

警告: If you are using an OEM version of Windows, this process is unauthorized by the end user license license. Indeed, the OEM license typically states the Windows install is tied with the hardware together. Transferring a Windows install to a virtual machine removes this link. Make thus sure you have a full Windows install or a volume license model before continuing. If you have a full Windows license but the latter is not coming in volume, nor as a special license for several PCs, this means you will have to remove the native installation after the transfer operation has been achieved.

A couple of tasks are required to be done inside your native Windows installation first, then on your GNU/Linux host.

Windows での作業

The first three following points comes from this outdated VirtualBox wiki page, but are updated here.

• Remove IDE/ATA controllers checks (Windows XP only): Windows memorize the IDE/ATA drive controllers it has been installed on and will not boot if it detects these have changed. The solution proposed by Microsoft is to reuse the same controller or use one of the same serial, which is impossible to achieve since we are using a Virtual Machine. MergeIDE, a German tool, developped upon another other solution proposed by Microsoft can be used. That solution basically consists in taking all IDE/ATA controller drivers supported by Windows XP from the initial driver archive (the location is hard coded, or specify it as the first argument to the .bat script), installing them and registering them with the regedit database.

• Use the right type of Hardware Abstraction Layer (old 32 bits Windows versions): Microsoft ships 3 default versions: Hal.dll (Standard PC), Halacpi.dll (ACPI HAL) and Halaacpi.dll (ACPI HAL with IO APIC). Your Windows install could come installed with the first or the second version. In that way, please disable the Enable IO/APIC VirtualBox extended feature.

• Disable any AGP device driver (only outdated Windows versions): If you have the files agp440.sys or intelppm.sys inside the C:\Windows\SYSTEM32\drivers\ directory, remove it. As VirtualBox uses a PCI virtual graphic card, this can cause problems when this AGP driver is used.

• Create a Windows recovery disk: In the following steps, if things turn bad, you will need to repair your Windows installation. Make sure you have an install media at hand, or create one with Create a recovery disk from Vista SP1, Create a system repair disc on Windows 7 or Create a recovery drive on Windows 8.x).

Disk2vhd を使って Windows パーティションを複製

Boot into Windows, clean up the installation (with CCleaner for example), use disk2vhd tool to create a VHD image. Include a reserved system partition (if present) and the actual Windows partition (usually disk C:). The size of Disk2vhd-created image will be the sum of the actual files on the partition (used space), not the size of a whole partition. If all goes well, the image should just boot in a VM and you won't have to go through the hassle with MBR and Windows bootloader, as in the case of cloning an entire partition.

GNU/Linux での作業

ヒント: Skip the partition-related parts if you created VHD image with Disk2vhd.

• Reduce the native Windows partition size to the size Windows actually needs with ntfsresize available from ntfs-3g. The size you will specify will be the same size of the VDI that will be created in the next step. If this size is too low, you may break your Windows install and the latter might not boot at all.

Use the --no-action option first to run a test:

# ntfsresize --no-action --size 52Gi /dev/sda1

If only the previous test succeeded, execute this command again, but this time without the aforementioned test flag.

• Install VirtualBox on your GNU/Linux host (see #Installation steps for Arch Linux hosts^{[リンク切れ: セクションが存在しません]} if your host is Arch Linux).

• Create the Windows disk image from the beginning of the drive to the end of the first partition where is located your Windows installation. Copying from the beginning of the disk is necessary because the MBR space at the beginning of the drive needs to be on the virtual drive along with the Windows partition. In this example two following partitions sda2 and sda3will be later removed from the partition table and the MBR bootloader will be updated.

# sectnum=$(( $(cat /sys/block/''sda/sda1''/start) + $(cat /sys/block/''sda/sda1''/size) ))

Using cat /sys/block/sda/sda1/size will output the number of total sectors of the first partition of the disk sda. Adapt where necessary.

# dd if=''/dev/sda'' bs=512 count=$sectnum | VBoxManage convertfromraw stdin ''windows.vdi'' $(( $sectnum * 512 ))

We need to display the size in byte, $(( $sectnum * 512 )) will convert the sector numbers to bytes.

• Since you created your disk image as root, set the right ownership to the virtual disk image:

  # chown your_user:your_group windows.vdi

• Create your virtual machine configuration file and use the virtual disk created previously as the main virtual hard disk.

• Try to boot your Windows VM, it may just work. First though remove and repair disks from the boot process as it may interfere (and likely will) booting into safe-mode.

• Attempt to boot your Windows virtual machine in safe mode (press the F8 key before the Windows logo shows up)... if running into boot issues, read #Fix MBR and Microsoft bootloader. In safe-mode, drivers will be installed likely by the Windows plug-and-play detection mechanism view. Additionally, install the VirtualBox Guest Additions via the menu Devices > Insert Guest Additions CD image.... If a new disk dialog does not appear, navigate to the CD drive and start the installer manually.

• You should finally have a working Windows virtual machine. Do not forget to read the #Known limitations.

• Performance tip: according to VirtualBox manual, SATA controller has a better performance than IDE. If you can't boot Windows off virtual SATA controller right away, it is probably due to the lack of SATA drivers. Attach virtual disk to IDE controller, create an empty SATA controller and boot the VM - Windows should automatically install SATA drivers for the controller. You can then shutdown VM, detach virtual disk from IDE controller and attach it to SATA controller instead.

MBR と Microsoft ブートローダーの修復

If your Windows virtual machine refuses to boot, you may need to apply the following modifications to your virtual machine.

• Boot a GNU/Live live distribution inside your virtual machine before Windows starts up.

• Remove other partitions entries from the virtual disk MBR. Indeed, since we copied the MBR and only the Windows partition, the entries of the other partitions are still present in the MBR, but the partitions are not available anymore. Use fdisk to achieve this for example.

fdisk ''/dev/sda''
Command (m for help): a
Partition number (''1-3'', default ''3''): ''1''

• Write the updated partition table to the disk (this will recreate the MBR) using the m command inside fdisk.

• Use testdisk (see here for details) to add a generic MBR:

# testdisk > Disk /dev/sda...' > [Proceed] >  [Intel] Intel/PC partition > [MBR Code] Write TestDisk MBR to first sector > Write a new copy of MBR code to first sector? (Y/n) > Y > Write a new copy of MBR code, confirm? (Y/N) > A new copy of MBR code has been written. You have to reboot for the change to take effect. > [OK]

• With the new MBR and updated partition table, your Windows virtual machine should be able to boot. If you are still encountering issues, boot your Windows recovery disk from on of the previous step, and inside your Windows RE environment, execute the commands described here.

既知の制限

• Your virtual machine can sometimes hang and overrun your RAM, this can be caused by conflicting drivers still installed inside your Windows virtual machine. Good luck to find them!
• Additional software expecting a given driver beneath may either not be disabled/uninstalled or needs to be uninstalled first as the drivers that are no longer available.
• Your Windows installation must reside on the first partition for the above process to work. If this requirement is not met, the process might be achieved too, but this had not been tested. This will require either copying the MBR and editing in hexadecimal see VirtualBox: booting cloned disk or will require to fix the partition table manually or by repairing Windows with the recovery disk you created in a previous step. Let us consider our Windows installation on the second partition; we will copy the MBR, then the second partition where to the disk image. VBoxManage convertfromraw needs the total number of bytes that will be written: calculated thanks to the size of the MBR (the start of the first partition) plus the size of the second (Windows) partition. { dd if=/dev/sda bs=512 count=$(cat /sys/block/sda/sda1/start) ; dd if=/dev/sda2 bs=512 count=$(cat /sys/block/sda/sda2/size) ; } | VBoxManage convertfromraw stdin windows.vdi $(( ($(cat /sys/block/sda/sda1/start) + $(cat /sys/block/sda/sda2/size)) * 512 )).