Re: Distinguishing identical devices

[Graeme Gill <graeme@colorstar.com.au>]

John R Pierce <pierce@hogranch.com> wrote:
> The usual convention is to sort them in bus/dev order and treat them as (for
> example) scsi channel 0, 1, 2, ...  So the first instance of a SCSI class
> controller would be scsi channel 0.  This is not unlike what Sun does on
> their workstations, where the channels are searched in an arbitrary order
> and the first one found is /dev/rdsk/c0xxxxxx, then /dev/rdsk/c1xxxxxx etc.

This is fair enough as far as it goes, but without
specific knowledge of the machine, you still won't
be able to tell which physical card is card 0 etc.
(A standard problem when you need to connect each
card to something).

A couple of ideas are:

Put a LED on each card
that is visible from the back panel, and to
have a feature in the driver that flashes
the LED of a chosen card. You could then
have an installation process that guides the
user through attaching the right cable to the
right card.

If each card has an individual electronic serial
number, another idea would be to label the
card with the last few digits of the serial
number. (This is assuming multiple cards
are likely to be consecutive).

Graeme Gill.