Date: Mon, 19 May 1997 11:05:33 -0400 From: Charles Henrich <henrich@crh.cl.msu.edu> To: Joerg Wunsch <joerg_wunsch@uriah.heep.sax.de> Cc: freebsd-scsi@FreeBSD.ORG Subject: Re: scsi library interface Message-ID: <19970519110533.07999@crh.cl.msu.edu> In-Reply-To: <19970519103618.LH45116@uriah.heep.sax.de>; from J Wunsch on Mon, May 19, 1997 at 10:36:18AM %2B0200 References: <19970518184034.10726@crh.cl.msu.edu> <19970519103618.LH45116@uriah.heep.sax.de>
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On the subject of Re: scsi library interface, J Wunsch stated: > As Charles Henrich wrote: > > > Who wrote the scsi interface commands? (e.g. scsi_open, scsi_build > > ..) I need to bang on them with some questions. > > Peter Dufault. He's also got a revamped library which he was asking > people to test. It's on hub's anon ftp area, if i'm not mistaken. Cool. > > Also, in general when do you use raw mode devices vs. block mode vs > > the .ctl devices? > > Buffered (`block') devices: to mount a filesystem over them. Nothing > else. (Well, swapon(8) is in the same boat.) > > Raw (`character') devices: any other regular (i.e. read(2)/write(2)) > IO. > > Control devices: raw SCSI commands. State of the device doesn't > matter then, e.g. you can open a control device for an unformatted > disk, but you can't open the raw or buffered device. Then why is it when you start sending raw SCSI read commands to rcd0.ctl behind which lives a Toshiba, you explode the SCSI bus, yet if you send them to /dev/cd0c things appear to work? (And with a plextor, both work!) Im confused.. -Crh Charles Henrich Michigan State University henrich@msu.edu http://pilot.msu.edu/~henrich
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