Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!usc!snorkelwacker!spdcc!ima!sludlum!stevel From: stevel@sludlum.ima.isc.com (stevel) Newsgroups: comp.unix.i386 Subject: Re: SCSI first disk Message-ID: <430@sludlum.ima.isc.com> Date: 27 May 90 14:24:43 GMT References: <361@denwa.uucp> Organization: /usr/lib/news/organization Lines: 32 jimmy@denwa.info.com (Jim Gottlieb) writes: >Common net wisdom seems to indicate that it is best to use a non-SCSI >drive as the first disk drive. Is there a safe way around this? I >would rather not use up slots for both an ESDI and a SCSI controller. Not True! I have only one disk on my system and it is a SCSI. There are people out there with several SCSI disks on one controller. 386/ix supports up to four drives on one SCSI controller. It assumes that tape drives take up another couple of LUNs and itself takes yet another. People who have had trouble configuring thier systems have been using NON-SCSI drives as 0 and 1 and then trying to put the SCSI in as drive 3 or higher. This requires getting /etc/partitions to be just right. I've never tried this so I can not give any advice on getting it right, but make sure you do the mkpart commands carefully. My advice is go for a SCSI only system. If you want real tape backup then you will not have to get another controller. The super fast disk transfer times of IDE or ESDI disks are outwieghed 3 to 1 by seek times. On top of that is the file system overhead is the limiting factor for a disk any faster than 15 Milisecond access times and 5 Megabit transfer rate. These speeds are too fast for improved throughput with a 386 system. This may not hold true for 25MHZ or 50Mhz 486 systems with an EISA or microchannel bus. Steve Ludlum Industrial Bytes & Bits Cambridge, MA ima!sludlum!stevel -- Steve Ludlum Industrial Bytes & Bits Cambridge, MA ima!sludlum!stevel