2TB and larger harddrives support state

[xerces8]

Hi!

With v3.0.8 VirtualBox supports virtual disks over 2TB in size:
SCSI: add support for virtual disks larger than 2TB

Is this support complete?
I mean the VirtualBox BIOS has no problems with reading above the 2TB mark?

I just tried to install Ubuntu 10.10 onto a 5TB virtual disk, and it has problems booting.

So before I go bother Ubuntu people, I want to check the state in VirtualBox.

Regards,
David

[Perryg]

VirtualBox 3.0.8 (released 2009-10-06)
SCSI: add support for virtual disks larger than 2TB

I have no idea how much over and I am not totally sure that Ubuntu can handle more than 3TB either. Try at 3TB and see what happens.

[xerces8]

In recent versions (4.x) the GUI prevents selecting/entering sizes over 2TB.

The competition can handle about 60 TB (VMWare, Hyper-V) now.

What is the official max capacity for VDI? I took a (quick) look into the UserManual and did not find any definition of this.

Regards,
David

[mpack]

Practically speaking, VDI has no size limit that will be approached any time soon.

Limitations come from elsewhere, e.g. virtual BIOS type, partition map type, guest OS.

2TB is the largest disk you can have which uses a legacy MBR and 512 byte sectors. As these are the most portable parameters I would avoid exceeding them if I could.

[xerces8]

I mean the "final result", VirtualBox as a whole.

More than 2TB: yes? no? unknown?

[mpack]

VirtualBox isn't a whole, it's a menu. The disk size constraint comes from your VM recipe.

[xerces8]

So you are saying there is no 2TB limit?

[mpack]

AFAIK, no. Not in VirtualBox, at least not by design. The constraints are in guest software, not in the (virtual) hardware. E.g. a legacy MBR doesn't support more than 2^32 sectors either in the physical or virtual worlds.

[gwardell]

Hi,

The last I looked Virtual Box doesn't have a UEFI BIOS so you are stuck with a legacy BIOS and therefor an MBT boot disk.

The other disks can be GPT and there can be larger than 2TB.

BTW, there are other benefits to GPT besides breaking the 2Tb barrier. e.g. greater resiliency to damaged directory structures, more than four partitions.

Gary

[xerces8]

Isn't there an experimental EFI BIOS?

From the manual:

3.12 Alternative firmware (EFI)

Starting with release 3.1, VirtualBox includes experimental support for the Extensible Firmware
Interface (EFI), which is a new industry standard intended to eventually replace the legacy BIOS
as the primary interface for bootstrapping computers and certain system services later.

[Perryg]

Experimental EFI is available for Mac and does work in Linux. I have never been able to make it work in Windows.

[mpack]

The last I looked Virtual Box doesn't have a UEFI BIOS so you are stuck with a legacy BIOS and therefor an MBT boot disk.

Well, your axiom is wrong, but even if it was correct your conclusion is still wrong in general (though it happens that it's currently correct for VirtualBox).

An MBR can't address more than 2^32 sectors. However it can address drives larger than 2TB if you make the sectors larger, so called "advanced format". I should note however that I believe VirtualBox at present doesn't support larger sectors. I suspect this wasn't by design, I think it's just that the 512byte assumption is littered throughout the code.

[xerces8]

A short and concise answer here: viewtopic.php?f=1&t=46991

[mpack]

A short and concise answer here: viewtopic.php?f=1&t=46991

Well yes, though to a different question. You first post here asks if VirtualBox completely supports >2TB drives. That's an entirely different question than asking how to create one using VBoxManage.

[xerces8]

Yes, but it answers this:

In recent versions (4.x) the GUI prevents selecting/entering sizes over 2TB.

Also, my other question from the original post is : the VirtualBox BIOS has no problems with reading above the 2TB mark?

And... I guess I'll have to find the answer myself.