Help Please

[camerondad2003]

I'm trying to understand VHD. I understand dual booting but why VHD?

Please explain to me what it does?



Thanks

 

[Lordbob75]

VHD is a Virtual Hard Drive. This allows you to have multiple partitions inside another partition. Say you have a 1TB drive. Make it one big partition. Then you could make 100 ten gig VHDs for 100 different OSs.

Make sense?

~Lordbob

 

[camerondad2003]

Kinda, but why not just make partitions in 10gb partitions like you said and just really install the different operating systems on them?

 

[Lordbob75]

Kinda, but why not just make partitions in 10gb partitions like you said and just really install the different operating systems on them?

Well there are a few reasons. First off, you can only have 26 extended partitions, 4 of which can be primary (for OSs). This means there is a limit. With VHDs, you can have as many as you want. So you can create, say, a 500 gig partition. Install the OS on it. Now, say, you need somewhere to store pictures, and another for video. You can make one VHD for each, and name them such. Now your boot menu will be cleaner as there is no other partitions to choose from.

These are especially useful if you want to use a VM. You can install an OS on VHDs, and boot a VM from them.

~Lordbob

 

[camerondad2003]

ok so basically its just emulation. You start off by installing windows 7 on the entire partition then you download an emulator and run the different rom files from it? and its just windows in another window?

 

[Lordbob75]

Uses

Virtual Hard Disks allow multiple operating systems to reside on a single host machine. This enables developers to test software on different operating systems without the cost or hassle of actual hardware. The ability to directly modify a virtual machine’s hard disk from a host server supports many applications, including:

• Moving files between a VHD and the host file system
• Backup and recovery
• Antivirus and security
• Image management and patching
• Disk conversion (physical to virtual, and so on)
• Life-cycle management and provisioning

[edit] Software using the VHD file format

The format is used for Microsoft Virtual PC and was also adopted by XenSource for what is now the Citrix XenServer hypervisor. The VHD format is used by Microsoft Windows Server 2008 which includes a hypervisor-based virtualization technology called Hyper-V. Hyper-V features offline VHD manipulation — providing administrators with the ability to securely access files within a VHD without having to instantiate a virtual machine. This provides administrators with granular access to VHDs and the ability to perform some management tasks offline.[2]
The VHD format is used by Windows Vista's Complete PC Backup feature found in the Business, Enterprise and Ultimate editions.
VirtualBox, part of Sun Microsystem's Sun xVM line supports VHD in versions 2 and newer, and can read VHD format files on a wide variety of operating systems.
VMware ESX Server supports the format as an alternative to its proprietary VMDK format.
Windows 7 and Windows Server 2008 R2 will include support for creating, mounting, and booting from VHD files.[3]

[edit] Supported formats

VHDs are implemented as files that reside on the native host file system. The following types of VHD formats are supported by Microsoft Virtual PC and Virtual Server:

• Fixed hard disk image - a file that is allocated to the size of the virtual disk.
• Dynamic hard disk image - a file that at any given time is as large as the actual data written to it, plus the size of the header and footer.
• Differencing hard disk image - a set of modified blocks in comparison to a parent image.

Hope that helps a little. It is a little unclear as to its uses to me, but I use one for my Seven x32 VM.

~Lordbob