Dual simultaneous USB flash drive between a PC and an embedded system?
Solution 1:
This is an interesting problem even if it is a few years old.
I've seen people use single board computers with USB-OTG ports as a storage device allowing a portion of its drive appear as USB storage to another computer. The files could be modified by both systems but care had to be taken to avoid both writing at once. The Linux "USB gadgets" project is one scheme to allow this.
I've seen USB switches that could help in avoiding the motions of having to move the drive back and forth. Some could be controlled by software to allow scripting.
If some people that knew enough low level hardware and firmware then they could create a dual port USB drive. Maybe do this on some kind of FPGA development board, or crack open some flash drives and put a soldering iron to them. I have some ideas but I'm not sure I should give my half baked ideas to anyone else.
The option one would choose depends on where one feels most comfortable. Linux USB gadgets would be a software heavy solution. Some kind of FPGA is a firmware solution. Hacking up some flash drives with a xacto knife and a soldering iron is a hardware solution.
The link to the PC to PC USB transfer cable is broken so I don't know for sure what that's about. My guess is it's emulating a serial or network connection, not storage, and so would not likely work in this case. For one computer to serve up files to another that is expecting to see a USB drive would require something like the Linux USB gadgets and an OTG cable to work.
Again, I know this is old but I happened across it, found it interesting, and thought I might share ideas on where someone with a similar problem could look for solutions.