Return to BSD News archive
Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!nntp.coast.net!dispatch.news.demon.net!demon!feed1.news.erols.com!cpk-news-hub1.bbnplanet.com!news.bbnplanet.com!EU.net!sun4nl!server1.adam.ixe.net!news2.euro.net!wirehub!newsgate.cistron.nl!news.iac.net!news.kudra.com!tabby.kudra.com!robert From: robert@tabby.kudra.com (Robert Sexton) Newsgroups: comp.periphs.scsi,comp.unix.bsd.freebsd.misc Subject: Re: Bizarre SCSI problem (3 disks work, 4 don't) (2940UW/Quantum Atlas II) Followup-To: comp.periphs.scsi,comp.unix.bsd.freebsd.misc Date: 13 Feb 1997 04:04:56 GMT Organization: Kudra.Com Web Services Message-ID: <5du3t8$jug$1@tabby.kudra.com> References: <5d7201$qa@gosset.maths.tcd.ie> NNTP-Posting-Host: localhost.kudra.com X-Newsreader: TIN [version 1.2 PL2] Lines: 28 Xref: euryale.cc.adfa.oz.au comp.periphs.scsi:70409 comp.unix.bsd.freebsd.misc:35416 Alan Judge (ajudge@maths.tcd.ie) wrote: : I have a really odd (in my experience, at least) SCSI problem. The setup is : a PC (running FreeBSD 2.2-BETA) containing an Adaptec 2940UW. No internal : disks. The external 68-pin connector is connected to a case containing 4 : Quantum Atlas II disks. Inside the case, the 4 disks are chained together : on a ribbon cable. The case is terminated with an external active : terminator, and the 2940 termination is set to automatic. Two potential problems come to mind: 1. Is your SCSI Bust within Length Limits? Ultra means cables can only be half as long as Fast SCSI. 2. Are all drives supplying terminator power? The SCSI Standard says that the controller supplies termpwr, but I have found that its not always enough. : The 4 disks are numbers 0..3. When *any* three disks are connected to : the ribbon cable, everything works fine; I can access and use the : disks. When all four are connected, the SCSI system fails quite : quickly. The usual symptoms are a lockup where one of the disk : activity lights will remain on. This is a symptom of termination problems. -- Robert Sexton - robert@kudra.com As a software development model, Anarchy does not scale well. -Dave Welch