Date: Tue, 27 Oct 1998 19:42:56 +0100 (CET) From: Wilko Bulte <wilko@yedi.iaf.nl> To: peter@taronga.com (Peter da Silva) Cc: scsi@FreeBSD.ORG Subject: Re: Do we support > 32 drives yet? Message-ID: <199810271842.TAA25162@yedi.iaf.nl> In-Reply-To: <199810271324.HAA10344@bonkers.taronga.com> from Peter da Silva at "Oct 27, 98 07:24:02 am"
next in thread | previous in thread | raw e-mail | index | archive | help
As Peter da Silva wrote... > In article <199810261835.TAA13230@yedi.iaf.nl>, > Wilko Bulte <wilko@yedi.iaf.nl> wrote: > >??? The HSZ50 backend is not wide scsi. In a BA355 type enclosure you can > >have 24 disks, using BA35[06] device shelves you can have 6 (backend > >channels) * 7 (disks per shelf) is 42 disks. Using redundant power supplies > >in your BA35[06] you are limited to 6 * 6 = 36 disks. I don't see how > >you get to 84 disks. > > You can run two HSZ50s on a single SCSI bus, with 7 disks on each shelf, for > a total of 84 disks. You can only assign them to 56 unique LUNs between the If I understand you right you then have 1x HSZ50 per M-shelf (controller shelf). Having 2x HSZ50 each in it's own controller shelf gives you the 84 disks in a total of 12 device shelves. It is not really recommended (performancewise) to have multiple HSZ50 sharing a single FWD scsi host bus. For HSZ50 you can get away with this, for HSZ[78]0 you are really throttling things. And a config like this leaves you out of luck in case a HSZ50 dies ... Dual redundant pairs of HSZ50 make it considerably more costly. > two units, though. Digital UNIX doesn't support more than 7 IDs per bus, > unfortunately, but on FreeBSD you could fit four HSZ50s for 168 drives > over 112 LUNs. You'd run out of minor numbers before you'd populated the > third host adapter. Steel (DUnix 5.0) will probably have wide scsi addressing I suppose. > Yes, this is way extreme. There's cheaper ways of doing it, but the sparse > address space and nailed-down device numbers of the System V model is handy > when you have a lot of hot-pluggable hardware. It's expensive, but not extreme in the sheer size of the config. Running HSZ as a sort of glorified SCSI multiplexer is sort of eh... special ;-) Wilko _ ______________________________________________________________________ | / o / / _ Bulte email: wilko@yedi.iaf.nl |/|/ / / /( (_) Arnhem, The Netherlands WWW : http://www.tcja.nl ______________________________________________ Powered by FreeBSD __________ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199810271842.TAA25162>