What is HDD (Parallels Hard Disk) ?

[Netspiderz]

Hello,

While installing a new virtual machine, I am presented with several hard disk options, one of them is HDD (Parallels Hard Disk). I tried to Google it, but I couldn't find anything useful about it. Could anyone point me in the right direction?

Thanks

[Sasquatch]

Well, were your other options VDI, VMDK and VHD? It's nothing more than a file format that represents the virtual hard drive. See chapter 5.2 of the User Manual for more information.

[mpack]

If you don't know what they are then you can safely ignore the non-VirtualBox options. Select VDI, the default. It's the best choice.

[gmlew]

This is an old topic but still on the top of a google search.

Parallels Hard disk is a type of hard disk typically created by a piece of software called Parallels.
Parallels (for desktop) is, in a nutshell, the same type of product as Virtualbox. It is a VM for running
a MS Windows guest on a Mac host. Parallels hard disk is only applicable if you want to be able to use
it on Mac host and use some form of the Parallels software.
If this sounds like what you need ... Do more research on the specific Guest OS/Host OS/Parallels software combination requirement

If you are not sure you might choose VDI, Fixed size(for untested compatibility), with the size computed as:

• Initial OS size (*2 or*3 for bloat)
• + configured RAM size*1.5 for swap
• + desired user space
• = Total fixed.

Example: a common versatile *Nix box might be a VDI with 60GB total minus ~8GB for swap and another ~10GB for OS (~3GB*3)
Leaves you with a very comfortable ~40+GB userspace all on the same disk.

These are some common Virtual disk types.

• VDI= Oracle Vbox mountable hard disk (default choice for for most users of Oracle's Virtualbox)
• VHD= Microsoft Windows OS mountable hard disk -Windows VM, Hyper-V, Windows OS (other than a physical
  USB drive) it's a nice choice for a second storage drive in a Vbox VM as it can be mounted
  natively on NTFS compatible Windows systems when the VM IS OFF
• VMDK= VMware mountable Hard disk (VMware is EMC's-->Dell's VM)
• HDD= This is the Parallels HD in this post.
• Qcow= QEMU mountable hard disk (Qemu is also a type of VM) wiki.qemu(dot)org
• Qed= QEMU mountable hard disk (enhanced disk)

These are not necessarily all only mountable by said software. Is just their primary uses and origins.
There are MANY other considerations for Vdisk types and configurations.

As a side note. ONLY Oracle's Virtualbox (w/o ext pack) and QEMU's VM can be configured and licensed as GPL !

[mpack]

Do not choose fixed size VDI.