OK, I got Mirrordir working on my Linux box (RH7.1) and got the v116 hijack kernels loaded on both players. I connected a console to the 'slave' Empeg, and dropped to the shell and did 'rw' and 'rwm.' I then started this operation:

FooServ> mirrordir ftp://player1/drive0/fids/ ftp://player2/drive0/fids/

It worked fine for a while, copying about ~200 files or so, then I started getting "Can't open file for writing" and "permission denied" errors. I aborted the transfer and rebooted. I got "Can't unmask IDE device" on the slave unit, so I removed the power and rebooted again. It rebuilt the database and showed however many songs had been downloaded.

So no harm was done, but it didn't copy correctly either. The unit was in the shell, so I fail to see how anything in the fids directory could be locked, but I beseech those of greater wisdom to impart some token unto me..

If I can get this working, I think I can write a windows application to do the work that MirrorDir is doing, at least for the empeg special case..