[2183] in linux-scsi channel archive
Re: More than one SCSI controler & SCSI_IOCTL_GET_IDLUN
daemon@ATHENA.MIT.EDU (Joerg Schilling)
Sat Jul 19 18:03:28 1997
Date: Sun, 20 Jul 1997 00:00:15 +0200
From: schilling@fokus.gmd.de (Joerg Schilling)
To: lnz@dandelion.com, schilling@fokus.gmd.de
Cc: eric@andante.jic.com, linux-scsi@vger.rutgers.edu, tn@bv.rz.fh-muenchen.de
>I must be missing something here, but I'd like to know why a user program needs
>to know the SCSI bus number at all. The LUN is necessary because it must go in
>the CDB, but I don't see how the SCSI bus number matters to a user program.
>The user must specify the /dev/sg<x> SCSI generic device, which makes the
>mapping to bus and Target ID automatic.
You are looking at programs Linux centric. The /dev/sg driver is bad and
must be replaced anyway because it does not allow to sense most of the
error conditions. For that reason /dev/sg is a bad thing to compare software
against.
My /dev/scg driver that I made for SunOS in 1986 has one device per SCSI bus.
Cdrecord has been ported from SunOS to Linux.
In order to be able to have the same user interface for SunOS and Linux
I definitely need the Bus number.
Joerg
http://www.fokus.gmd.de/usr/schilling ftp://ftp.fokus.gmd.de/pub/unix
