Add support for USB hard disk images.

[ppgrainbow]

I don't know if this is a good suggestion or not, but I would like to see VirtualBox implement the ability to create USB hard disk images.

I noticed that that QEMU is the only PC emulator that has the ability to create the hard disk images and attach it to a emulated USB device.

It is unfortunate that other PC emulators don't have that USB hard disk image support.

What do you think about this idea?

(Between late March 2007 and last Christmas I ran a older version of Windows on QEMU with a 8 GB hard drive and a 2 GB hard disk image attached to a emulated USB port, before switching to Virtual PC).

[mpack]

I don't know if this is a good suggestion or not, but I would like to see VirtualBox implement the ability to create USB hard disk images.

You mean like when you mount a CD or DVD ISO image as virtual optical drive, except it's a USB flash drive?

What would be the advantage of that, compared to attaching a second VDI hard disk? The advantage of the CD/DVD feature is that it supports a standard distribution format, ie. ISO. I don't think there's any equivalent for USB. When you need a more flexible disk size (and writeable) the .VDI file seems fine to me.

[TerryE]

+1

I just can't see what the functional advantages of having a virtual USB HDD as opposed to a virtual IDE HDD. Perhaps you could explain what I am missing here?

[Sasquatch]

I see the advantage of it. If you run multiple Guest systems and want to share some files between one and the other, but don't want to set up a network share or shutdown the guest each time you want to transfer files, it's a real good use for this. While the VM is still running, you can unmount the drive and mount it in the other Guest. You can even transfer the files when you use saved states (of course you have to unmount the 'usb' drive first before going to saved state).
It can even be used as a backup disk, to save the install images for example.

[ppgrainbow]

I don't know if this is a good suggestion or not, but I would like to see VirtualBox implement the ability to create USB hard disk images.

You mean like when you mount a CD or DVD ISO image as virtual optical drive, except it's a USB flash drive?

What would be the advantage of that, compared to attaching a second VDI hard disk? The advantage of the CD/DVD feature is that it supports a standard distribution format, ie. ISO. I don't think there's any equivalent for USB. When you need a more flexible disk size (and writeable) the .VDI file seems fine to me.

To clarify this.

When you create a virtual disk image (VDI) and mount it onto a emulated USB device, it will be treated as a virtual USB flash drive.

Imagine this...if you open up VirtualBox, select Windows XP as a guest OS (assuming that you have it) and then under Settings, you would have a option to either mount a virtual hard disk image such as (USB.vdi) and use it as a emulated USB device or use one of the existing physical USB devices.

QEMU, has been using hard disk images as a emulated USB device for a while and I have a strong feeling that VirtualBox should be the next PC emulator to do that.

[ppgrainbow]

+1

I just can't see what the functional advantages of having a virtual USB HDD as opposed to a virtual IDE HDD. Perhaps you could explain what I am missing here?

TerryE, I've used QEMU for nine months and there was a option to create a hard disk image and use it as a virtual USB HDD and when I made the switch to virtual PC, there was no USB support at all.

I'm gonna look up some commands to see how virtual USB hard drives were done under QEMU later in the day.

Anyways, what I'm seeing is that if you have a guest operating system (such as Windows XP), there would be options to either mount a virtual HDD to use it as a emulated USB device (hence it would become a virtual USB HDD) or use a physical USB device as I explained this clearly to another user.

(All three of my physical USB devices that are currently shared through a network drive (4 GB flash drive, 2 GB compact flash card and the 2 GB memory card reader) are all using 3.18 GB out of 7.63 GB total and it would be too good of idea to back up all of the data there.)

[ppgrainbow]

I see the advantage of it. If you run multiple Guest systems and want to share some files between one and the other, but don't want to set up a network share or shutdown the guest each time you want to transfer files, it's a real good use for this. While the VM is still running, you can unmount the drive and mount it in the other Guest. You can even transfer the files when you use saved states (of course you have to unmount the 'usb' drive first before going to saved state).
It can even be used as a backup disk, to save the install images for example.

That sounds like a awesome idea since no one else has ever suggested virtual USB hard drives before. I'm even predicting that people would consider installing Firefox Portable on a virtual USB HDD.

I'll file a feature request report to see what the folks at Sun Microsystems say about this.

[mpack]

I see the advantage of it. If you run multiple Guest systems and want to share some files between one and the other ...

You mean, support removeable virtual drives? I guess I can see that some people could have a use for that. It could be very fiddly though, unless the GUI made it a nice feature, eg. an icon to represent the virtual USB stick(s), and virtual USB ports beside each VM. You drag one onto the other to plug/unplug drives.

[TerryE]

Quite honestly in reality, I am not sure what this really brings over samba shares and loop mounting VDIs in the host. Yes, there may be some delta benefit but is it really that worthwhile considering the development effort and other priorities?

[ppgrainbow]

Quite honestly in reality, I am not sure what this really brings over samba shares and loop mounting VDIs in the host. Yes, there may be some delta benefit but is it really that worthwhile considering the development effort and other priorities?

It's hard to tell if it's really worthwhile to consider the development of other priorities...

But what does samba shared and loop mounting VDIs have to do with this?

[ppgrainbow]

I see the advantage of it. If you run multiple Guest systems and want to share some files between one and the other ...

You mean, support removeable virtual drives? I guess I can see that some people could have a use for that. It could be very fiddly though, unless the GUI made it a nice feature, eg. an icon to represent the virtual USB stick(s), and virtual USB ports beside each VM. You drag one onto the other to plug/unplug drives.

That's correct. Both Bochs and Qemu have support for virtual USB hard drives. Other emulators don't.

[mpack]

Yes, there may be some delta benefit but is it really that worthwhile considering the development effort and other priorities?

Quite honestly, although the feature would be cute, I'm not entirely convinced that it offers much that can't be handled by sharing a folder on the host. The argument "other software does it, so we should do it too" doesn't sway me either.

The one area where I can see it being useful is when the VDI file in question really is on a USB stick, as this could then allow movement of files between VMs on different hosts where there is no LAN - without all the messing about and jumping through all the hoops (dismount, mount, register) than VBox presents for fixed drives.

As to development effort: I wouldn't have thought this feature required a huge amount of new code, but that doesn't mean I would give it a high priority.

[netsecurity]

What I would like to do is use the 20G laptop drive that I have mounted in a USB connected case to create the VirtualBox so I could move the installation form one Windoze machine to another and start VB over again on the other machine.

The reason for this is I'd like to have a W2K and an XP install on VirtualBox with a bunch of network detection and mapping tools that I could capture the layout of subnets without having to install them on a physical machine in each subnet for creating a map of a complex network where medical data is kept separated from financial, CC, medical devices, access points, etc., by subnetting. It would also do banner grabs, port scans, check SNMP MIBS for installed software, and use some commercial tools such as AirMagnet that all run on Windoze.

I could boot from a Live CD, I guess, but I've had some problems with that not always discovering or being able to access the hardware that is running on a machine, then I have to spend time either chasing the problem or try different Live CDs. Using different Live CDs then creates the problem ow where I keep the tools I want? Do I have to make special Live CDs of several distros and install the tools, not all of which are Linux tools?

The virtual box idea makes sense in that once I get one going on one machine it should not be all that different on a different Windoze box.

It doesn't seem like that is what is being talked about, but then I'm very new to VB, so pointers would be most welcome.

Best,

netsecurity

[ppgrainbow]

What I would like to do is use the 20G laptop drive that I have mounted in a USB connected case to create the VirtualBox so I could move the installation form one Windoze machine to another and start VB over again on the other machine.

The reason for this is I'd like to have a W2K and an XP install on VirtualBox with a bunch of network detection and mapping tools that I could capture the layout of subnets without having to install them on a physical machine in each subnet for creating a map of a complex network where medical data is kept separated from financial, CC, medical devices, access points, etc., by subnetting. It would also do banner grabs, port scans, check SNMP MIBS for installed software, and use some commercial tools such as AirMagnet that all run on Windoze.

I could boot from a Live CD, I guess, but I've had some problems with that not always discovering or being able to access the hardware that is running on a machine, then I have to spend time either chasing the problem or try different Live CDs. Using different Live CDs then creates the problem ow where I keep the tools I want? Do I have to make special Live CDs of several distros and install the tools, not all of which are Linux tools?

The virtual box idea makes sense in that once I get one going on one machine it should not be all that different on a different Windoze box.

It doesn't seem like that is what is being talked about, but then I'm very new to VB, so pointers would be most welcome.

Best,

netsecurity

What I saying is that I'm suggesting the ability to mounting disk images as a virtual USB hard drive. That way if you want to share files without having to set up network shares or turn off the guest machine incase you want to transfer files.

(If you were to transfer files to a virtual USB hard drive under Windows 2000 or Windows XP guest and put it on Windows 98 or Windows Me, the virtual HDD has to be formatted as either a FAT16 or a FAT32 partition since those OSes cannot read the NTFS from a NT-based operating system.)

QEMU and Bochs both have that option.

[vogel]

retracted