Using a small linux box, I need to simulate a usb thumb drive. Supposing somebody here must have done that long ago, would you share the lessons you learned, please?

Thankyou

Eno Compton

Simulate for what purpose? If you're just looking for a small filesystem which you will mount and un-mount manually you could use a loopback filesystem (i.e. a filesystem in a file). If you want to simulate the plugging of an actual device, I don't know. Perhaps there is some option to do this in one of the virtual machine programs?

We produce airborne disks for various avionics also of our manufacture. The disks need to be loaded by a terrestrial device. For this function, we envision a tiny linux box that interfaces to the disk and simulates a usb disk. The operator would plug our box, via a usb cable, into an ordinary windows box on which our airborne disk would appear just like any thumb drive, albeit much larger.

From that point, the operator could drag and drop data on our disk just as he would an ordinary usb drive.

What's a virtual machine?

Eno

Ah, so you want Linux to have a usb cable coming from your Linux box, which when connected to another computer will act like a UMS (universal mass storage) device? Googling is tough because the much more common use of plugging a UMS device into linux swamps the hits.

You might have some luck asking the question in an embedded linux specialist group. The forums at LinuxDevices is probably a good place to start. If you find something, please post a link in this thread - I'd like to know.

Virtual machines are programs which pretend to be computers. You can install operating systems "into" them and all sorts of similar stuff. Some emulate various bits of hardware, such as USB ports. Examples of x86 architecture virtual machines are vmware or qemu. If you want to prototype some hardware in software, using virtual machines might be one way to go, but unless you're really into the low level stuff it's probably not appropriate.

I think all you need is a USB file transfer cable:

http://catalog.belkin.com/IWCatProdu...duct_Id=275561

no drivers required. Its about $100 USD I think. It is designed to connect two computers and transfer files between them. I haven't tried this myself. You will likely have to create a VFAT partition on the linux box for a windows box to read and write to, just as you do with a USB flash disk.

The USB file transfer cable is what is known as a host to host cable. I've never used one but linux recognizes these cables as network devices. I assume it would be possible to create a driver using these cables to simulate a mass storage device. Not sure it is worth the effort. Googling didn't really find anything.