Fedora 15 + scsi tape drive

Chris Adams cmadams at hiwaay.net
Sat Oct 15 04:31:11 UTC 2011


Once upon a time, Rick Stevens <ricks at nerd.com> said:
> Back in the day, the SCSI controller was assigned ID 7 and typically
> tape drives were given ID 4.  Hard drives were usually 0, 1, 2, and 3.
> IDs 5 and 6 were left for the user.  Don't ask me why...I suppose they
> figured no one would ever need more than four hard drives.  Then again,

While generally drives were given the low numbers (for boot order on
PCs), most of the drives I saw had the same 3 jumpers to assign any ID
(including 7 if you renumbered the SCSI card for any reason), the
rotating switch, or the up/down push-buttons.  There wasn't any actual
reservation of the numbers for specific devices.  IIRC I did see one
external tape drive that could only be 5 or 6 though (just because of
convention).

> Then again,
> Gates said we'd never need more than 640K of RAM.

No, he didn't.

> Older Linux kernels carried along the SCSI ID as the device name,

No, Linux always assigned SCSI devices in order from the start (e.g.
sda, sg0, sr0, st0).  Assigning with the ID was always something
controversial, because on one hand, it would have given fixed device
names (when that was desired for the more "enterprise-level" SCSI, when
IDE always used hda for primary master, hdb for primary slave, etc.),
while on the other, there weren't enough device major/minor numbers (and
that assignment style never handled multiple buses or HBAs) to actually
do that.

Other OSes did it different, but not Linux, and certainly not any Fedora
version (as the OP said).  I'm pretty sure the only way Fedora would
have had st4 without st[0-3] would have been if there was a udev rule to
rename it.

-- 
Chris Adams <cmadams at hiwaay.net>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.


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