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Newsgroups: comp.unix.bsd.freebsd.misc Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!howland.erols.net!cs.utexas.edu!math.ohio-state.edu!news.physics.uiowa.edu!ljg From: ljg@PROBLEM_WITH_INEWS_GATEWAY_FILE (Larry Granroth) Subject: 5-bit limit on SCSI cd devices? X-Nntp-Posting-Host: hubbard.physics.uiowa.edu Message-ID: <E3I9Ln.ExB@sysadm.physics.uiowa.edu> Summary: can I have more than 32 SCSI cd devices? Keywords: SCSI cd cdrom driver Sender: news@sysadm.physics.uiowa.edu (News Administrator) Organization: The University of Iowa, Department of Physics and Astronomy X-Newsreader: TIN [version 1.2 PL2] Date: Sat, 4 Jan 1997 22:39:22 GMT Lines: 23 Xref: euryale.cc.adfa.oz.au comp.unix.bsd.freebsd.misc:33542 I would like to hang stacks of cheap SCSI CDROM changers on a FreeBSD 2.2 box, but there appears to be a limit of 32 device units built into the cd driver (a 5-bit CDUNIT). (BTW, MAKEDEV should probably be modified to allow units 0 through 31 in any case.) The PC is an old 486/66 with an Adaptec 1542 and (so far) a stack of 6 NEC MultiSpin 4Xc changers, each with 7 disk slots accessed by SCSI logical unit numbers for a total of 42 potential cd* devices. Is there any way to accomodate more SCSI cd devices? Could a clone of the current cd driver be used with a different set of device major/minor numbers? (I really don't know anything about this, but could some of the allocations for other type cd drivers be cannibalized?) If this problem is solved, I'd like to add more SCSI controllers and even more CDROM changers. How many SCSI controllers can I add (assuming they can be configured in wrt port addresses, etc.)? Thanks for any help. -Larry larry-granroth@uiowa.edu