From owner-freebsd-scsi Thu Dec 11 23:01:21 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id XAA25341 for freebsd-scsi-outgoing; Thu, 11 Dec 1997 23:01:21 -0800 (PST) (envelope-from owner-freebsd-scsi) Received: from misery.sdf.com (misery.sdf.com [204.244.210.193]) by hub.freebsd.org (8.8.7/8.8.7) with SMTP id XAA25334 for ; Thu, 11 Dec 1997 23:01:18 -0800 (PST) (envelope-from tom@sdf.com) Received: from tom by misery.sdf.com with smtp (Exim 1.73 #1) id 0xgOwK-0004u1-00; Thu, 11 Dec 1997 22:51:12 -0800 Date: Thu, 11 Dec 1997 22:51:10 -0800 (PST) From: Tom To: Harry Aulakh cc: Wilko Bulte , walcaraz@indy3.gstone.com, freebsd-scsi@freebsd.org Subject: Re: RAID on FreeBSD In-Reply-To: <3.0.32.19971211155601.0092e580@gw1.tesys.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-scsi@freebsd.org X-Loop: FreeBSD.org Precedence: bulk On Thu, 11 Dec 1997, Harry Aulakh wrote: > > RAID5 arrays of 5 drives is kinda of nice sweet spot. If you go much > >bigger, just use RAID0 over multiple RAID5. > > Please note that dual RAID support (dpt based) is not available under > FreeBSD(there are few other OS's which do support it), as per my > information.. Can someone verify that.. "dual RAID" is probably a misleading term. You can have multiple arrays with the FreeBSD dpt. I you want to stack arrays (ex. stripe multiple RAID5 arrays together), you can easily just use ccd, after all the hard part, RAID5 reliability, is being done by the controller. I believe the dpt support for stacked arrays, and arrays across is all handled in software within the driver anyhow. Tom