Date: Mon, 25 Aug 1997 23:24:51 -0700 (PDT) From: Simon Shapiro <Shimon@i-Connect.Net> To: (Timothy Phan) <tphan@asl.dl.nec.com> Cc: (AIC7770 List) <aic7xxx@FreeBSD.ORG> Subject: RE: multiple scsi device Message-ID: <XFMail.970825232451.Shimon@i-Connect.Net> In-Reply-To: <199708252113.QAA00414@aslws174.asl.dl.nec.com>
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Hi Timothy Phan; On 25-Aug-97 you wrote: > Hi, > > I hope that I'm sending this problem to the right group. Is there > some limitation or restriction on connect multiple scsi > devices and lenght of the scsi cable onto the adaptec? > > I'm currently have 2 internal harddrive, an internal > CDROM, and 2 external harddrive (total of 5) connected to the > adaptec control. Everything is recognized by the > control in Linux without any problem. In the last > few days, I've tried to add one addition external > harddrive (to make it 6 in total) and it is not being > recognized. > > If I removed one of the other, then it would be ok. > I've check the SCSI ID for each and they all have > its own uniq ID. All the cable I used seem to be OK because > if it is hooked up individually, then no problem. > Each of the external cable is about 2 feet in length and > the internal cable has 7 connector and I do not remember > its length. Justin is THE expert on the Adaptec. From my limited experience, I am peasently surprised 5 devices work reliably. Generally, for Single-Ended SCSI, ultra (20MHz) speeds, about 5 feet, 4 devices, active termination and at least two inches between devices is about right. >From the symptoms you describe, you just found out what we all knew all the time :-) Simon Yes, there are exceptions. I had 8 SCSI UW SE devices on an Adaptec 2940UW. They worked like that for several months.
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