Truthfully, I'm not, nor have ever been a hardware guy, only software.
That's why I asked if there's something specific I can see, count, etc
to determine whether something belongs to host0, host1 or host2. I'm
just confused, that's all. This all started because I was trying to
help a guy install his internal zip drive. I have one also, and devfs
screwed up my system, so I had to pund the books until I finally found a
workaround by creating the necessary directories and block devices. It
was quite an experience. He had host0 and host2 on his system, and I
couldn't figure out where to put the block device on his system. We
both finally gave up, I think.
Anyhow, thanks for the information, and BTW, it's for IDE
Robert
On Thu, 2003-01-16 at 11:02, Borzenkov Andrey wrote:
> [...]>
> > Secondly, in /dev, there is the common host0, host1 business.
>
> /dev/ide or /dev/scsi?
>
> I still
> > haven't figured out the logic for determining the hostx business. Is it
> > something I can visually see on the motherboard, or is it something I
> > can query my system about that will provide the answer?
> >
>
> Not likely. Both for IDE and SCSI system enumerates adapters and assigns
> them numbers, this happens dynamically. These are the numbers you get in
> /dev/ide/hostN or /dev/scsi/hostN.
>
> For IDE the system reserves first two entries for bootable IDE controllers
> which usually means "controller on motherboard" unless you have configured
> your system with CONFIG_BLK_DEV_OFFBOARD in which case also PCI cards may be
> bootable. So your first onboard controller is host0 and next PCI is host2..
> But if you happen to have bootable PCI controller it may well be host0.
>
> For SCSI it is just the order SCSI hosts are enumerated which depends on
> order in which modules for particular hardware is loaded. First found SCSI
> controller gets 0, next 1 etc.
>
> For IDE you can assign host number by using ideN=ports and for SCSI by using
> scshosts=driver1,driver2,... but you have no easy way to specify relative
> order of hosts sharing the same driver.
>
> In general physical<->logical device numbers in Linux sucks. Even Solaris
> manages it better in most respects. Hopefully it will change in 2.5 with
> devicefs.
>
> -andrey
--
Robert <racsw@xxxxxxxxxxxxxxx>
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