Limitação chata do boot nativo em VHD

Estive brincando neste fim de semana com o boot nativo de VHD no Windows 7, e acabei ficando bastante decepcionado com algumas limitações que eu não conhecia. Não me lembro se alguém já tinha me falado, mas só é possível bootar nativamente um VHD se o SO instalado nesse VHD for também o Windows 7 ou Windows Server 2008 R2. É fácil confundir essa limitação porque apenas o boot loader desses dois sistemas operacionais suportam bootar nativamente um VHD, mas em nenhum momento tinha ficado claro para mim que, dentro desse VHD, também só podem existir esses dois sistemas operacionais. Eu tentei fazer um dual boot com Linux em um VHD e, para a minha surpresa, não funcionou. Aí fui correr atrás de entender o porquê e me deparei com essa limitação.

De qualquer forma, seguem 7 aspectos interessantes que eu encontrei sobre o boot nativo de um VHD:

1. Any previous versions of Windows is not Supported

That actually includes Vista and Windows server 2008. Only Windows 7 and 2008 R2 are supported to VHD native boot. The reason behind is that native boot VHD requires significant changes to the OS and these changes are new in Windows 7.

2. BitLock and Hibernation are not supported

Because of the same reason, these two features that require to access at hard disk level are not supported in VHD environment.

3. It supports 3 types of VHD, but neither compression nor encryption can be applied on VHD for native boot

3 types of VHD that are supported are fixed, dynamic, and differencing. However, VHDs that have been compressed by NTFS or encrypted using EFS on the host volume are not supported for native boot.

4. Make sure having enough space for VHD

That’s particularly important when you use dynamic type of VHD for native boot. The BSOD will come visit you if you are trying to native boot a 10G VHD that is dynamically only 5G on a computer that only has 7G spare space left on the system.

5. Remote or USB storage is not supported

It’s just purely not supported. If you follow our step-by-step how to set up a VHD native boot instruction, you will actually notice that it’s just technically not possible specify the correct path to a remote or USB storage in the bcdedit.

6. VHD used for native boot is not upgradable

That’s the lesson I learned pretty hard. It’s just you cannot upgrade the Windows version in the VHD to a newer version.

7. It’s possible VHD native boot from Vista

While Vista in VHD for native boot is not supported, a Windows 7 VHD that native boots from Vista is totally possible, and here is how.

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