Return to BSD News archive
Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!news.mel.connect.com.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!howland.erols.net!www.nntp.primenet.com!nntp.primenet.com!nntp.uio.no!sn.no!news-stkh.gsl.net!news.gsl.net!news-lond.gsl.net!news.gsl.net!news-dc.gsl.net!news.gsl.net!news
From: John Lucas <jlucas@jnet.vi>
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: Adaptec 2940UW works *but* ...
Date: Tue, 10 Dec 1996 10:56:10 -0400
Organization: University of the Virgin Islands
Lines: 65
Message-ID: <32AD7A0A.2781E494@jnet.vi>
References: <32AC10E0.41C67EA6@jnet.vi> <58j5uv$h55@cantina.clinet.fi>
NNTP-Posting-Host: backen.uvi.edu
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 2.01 (X11; I; FreeBSD 2.1.0-RELEASE i386)
Mika Ruohotie wrote:
>
> In article <32AC10E0.41C67EA6@jnet.vi>, John Lucas <jlucas@jnet.vi> wrote:
> >After much trial and error, I was able to get FreeBSD v2.1.5-RELEASE to
> >work with the Adaptec 2940UW (PCI Ultra Wide) host adapter and the
> >Seagate ST32155W (Hawk XL 2GB Ultra Wide drive). The secret is use the
> >"dangerously dedicated" drive partitionining. Although I tried many
> >things I was not able to get FreeBSD to install (and boot) properly any
> >other way. Now I have a system with a theoretical transfer rate of
> >40MB/sec (!!).
>
> hmm? i've used 2940UW and 3940UW (differential even) for months, with
> several versions, last is with 2.1.5 (soon something else), several
> different drives, and havent yet seen _any_ problems...
>
That's great, what drives are you using? Motherboard? BIOS?
> and well, with one drive, and coz of the physic laws, you can not go
> anywhere near 40MB/sec, that's the maximum _scsibus_ speed you can have,
> i think you need about 5 hawks to get to the, again, physical limit
> (which comes from the clock speeds) ~32MB/sec... feel free to correct
> if that wasnt true... (can someone again tell me the way to calculate this?
> i remember reading articles that talk about spinning speeds and the
> amounts that it's possible to "drag" off from the disk, did depend the
> inner/outer sectors)
>
That is why I carefully used the term "theoretical transfer rate". I have no idea
what the actual transfer rate is, but I plan on benchmarking the throughput against
my "narrow" machine soon. BTW, from the specs for the ST32155W drive found on:
http://www.seagate.com/cgi-bin/view.cgi?/scsi/st32155w.txt
FORMATTED CAPACITY (MB) __________________2148
AVERAGE SECTORS PER TRACK ________________125 rounded down
ACTUATOR TYPE ____________________________ROTARY VOICE COIL
TRACKS ___________________________________33,408
CYLINDERS ________________________________4,176 user
HEADS ______PHYSICAL______________________8
DISCS (3.5 in) ___________________________4
MEDIA TYPE _______________________________THIN FILM
RECORDING METHOD _________________________RLL (0,4,4)
--> INTERNAL TRANSFER RATE (mbits/sec)________44 to 66
--> EXTERNAL TRANSFER RATE (mbyte/sec) _______40 Sync
SPINDLE SPEED (RPM) ______________________5,411
AVERAGE LATENCY (mSEC) ___________________5.54
BUFFER ___________________________________512 KByte
Read Look-Ahead, Adaptive,
Multi-Segmented Cache
INTERFACE ________________________________Ultra-SCSI
>
> > - When attempting to use default partitioning with FreeBSD using > the why not use the default?
Because, as I stated in the original post, I could not boot that way. I really don't
mind that I have a drive dedicated to FreeBSD.
--
| John Lucas jlucas@jnet.vi |
| Information Technology NIC Handle: JL423 |
| University of the Virgin Islands (809) 693-1216 |
| St. Thomas, VI 00802 http://www.jnet.vi/jlucas.html |