(brought back onlist)

Another example, USB again... From http://www.linuxjournal.com/article/7316

...

A lot of devices are very difficult to distinguish from another, e.g. EPSON has the same USB ID's for a lot of printer models and you need to query the printer information with a vendor specific protocol

Has the situation changed? Isnt the 'serial no.' you mention the same as the USB ID discussed above?

Ok, so it doesn't work for all USB devices. Mice are probably the same. Anything with a filesystem or a unique serial, or MAC address, etc, however is fine. So, ok, multiple identical printers are probably a problem. At this point you might have to resort to "get different printers", or "leave them plugged into the same USB port, perhaps on an external HUB", or "buy an external print server that does ethernet -> USB. In terms of sound cards[1], you could use the PCI ID to define the order in which sound cards are brought up. This doesn't change - or it shouldn't change, unless you have faulty/crazy hardware - unless you shift the physical slot the device is plugged into. [1] or anything, even including USB devices as long as you are prepared to put them on the same port every time. Use the USB *bus* ID in that case, not the PCI ID, obviously :)