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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!news.mel.connect.com.au!munnari.OZ.AU!spool.mu.edu!sol.ctr.columbia.edu!news.uoregon.edu!europa.chnt.gtegsc.com!news.kreonet.re.kr!usenet.kornet.nm.kr!agate!howland.reston.ans.net!newsfeed.internetmci.com!in1.uu.net!xplor!news.us.world.net!ns2.mainstreet.net!bug.rahul.net!a2i!rahul.net!a2i!dandelion.com!not-for-mail From: "Leonard N. Zubkoff" <lnz@dandelion.com> Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: CDROM Changers Date: 17 Dec 1995 20:18:01 -0800 Organization: Dandelion Digital Lines: 16 Sender: lnz@dandelion.com Message-ID: <4b2q1p$796@kelewan.dandelion.com> References: <BILLW.95Dec8181411@puli.cisco.com> <4adn77$gsg@mark.ucdavis.edu> <DJECMK.KqA@sysadm.physics.uiowa.edu> <4aga5j$ei@kelewan.dandelion.com> <4b2hp9$cv5@elliot.ics.uci.edu> NNTP-Posting-Host: dandelion.com NNTP-Posting-User: root In-reply-to: shettich@elliot.ics.uci.edu's message of 17 Dec 1995 17:56:57 -0800 In article <4b2hp9$cv5@elliot.ics.uci.edu> shettich@elliot.ics.uci.edu (Seth Hettich) writes: >The Nakamichi MBR-7 also appears as multiple LUNs and automatically >switches disks. No special SCSI commands are necessary with mine. What happens if you try to access 2 disks at the same time? Well, there is no truly simultaneous access, of course. The drive will swap one CD for another whenever the SCSI command it receives is not directed to the currently loaded CD-ROM. If the SCSI command timeouts in the kernel are set appropriately for the devices, then you will merely thrash the MBR-7 if two or more processes attempt simultaneous access to multiple CD-ROMs. If the timeouts are too short, then you'll have lots of failures. Leonard