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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!news.rmit.EDU.AU!news.unimelb.EDU.AU!munnari.OZ.AU!news.Hawaii.Edu!ames!enews.sgi.com!news.mathworks.com!worldnet.att.net!newsfeed.internetmci.com!cobalt.nvt.net!symbios.com!news From: Mark Johnson <mark.johnson@symbios.com> Newsgroups: comp.periphs.scsi,comp.sys.hp.hpux,comp.unix.bsd.misc Subject: Re: Changing block size of SCSI Hard disks ? Date: Tue, 18 Mar 1997 11:22:27 -0800 Organization: Symbios Logic Inc, Storage Systems Division Lines: 24 Message-ID: <332EEB73.5716@symbios.com> References: <5gkgn5$6jm@bmerhc5e.bnr.ca> <332E9F38.1C9D@nct.ch> NNTP-Posting-Host: msjohnso.ks.symbios.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Mailer: Mozilla 2.0 (Win16; I) Xref: euryale.cc.adfa.oz.au comp.periphs.scsi:73512 comp.sys.hp.hpux:56324 comp.unix.bsd.misc:2859 Markus Zingg wrote: > By reading page 3 and setting mode sense CDB byte 3 to 0x43 the drive > should tell you which bit's can be changed. If you read the SCSI specs, > they tell you that the drive shall return check condition if any of the > "reserved" or unchagable bit's are set. What I try to tell you is that > you may accidentialy set one of the unchangable bit's in page 3 and that > this is the cause of the error. In programming this stuff, the standard way of dealing with the unchangeable items is to bitwise-or each byte of the prospective mode select page against the changeables page retrieved as described. That will turn off any non- changeable items before the request is sent down. Note that the standard permits targets to save mode parameters on a logical unit basis, per-initiator basis, by initiator/lun pair, or simply make them universal. Know thy target; I would expect that if logical block size is changeable, it's probably universal but that certainly isn't required. -- Mark Johnson USnail: Symbios Logic, Inc E-mail: Mark.Johnson@symbios.com MetaStor Business Team Voice: (316) 636-8189 [V+654-8189] 3718 N. Rock Rd. Visit our web page: http://www.symbios.com Wichita, KS 67226