From owner-freebsd-isp Tue Jul 22 12:21:47 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id MAA20996 for isp-outgoing; Tue, 22 Jul 1997 12:21:47 -0700 (PDT) Received: from mail.webspan.net (root@mail.webspan.net [206.154.70.7]) by hub.freebsd.org (8.8.5/8.8.5) with ESMTP id MAA20981 for ; Tue, 22 Jul 1997 12:21:42 -0700 (PDT) Received: from orion.webspan.net (orion.webspan.net [206.154.70.5]) by mail.webspan.net (WEBSPAN/970608) with ESMTP id PAA14460; Tue, 22 Jul 1997 15:21:36 -0400 (EDT) Received: from orion.webspan.net (localhost [127.0.0.1]) by orion.webspan.net (WEBSPAN/970608) with ESMTP id PAA11972; Tue, 22 Jul 1997 15:21:35 -0400 (EDT) To: Dev Chanchani cc: freebsd-isp@FreeBSD.ORG From: "Gary Palmer" Subject: Re: pseudo-device ccd In-reply-to: Your message of "Tue, 22 Jul 1997 12:27:41 EDT." Date: Tue, 22 Jul 1997 15:21:35 -0400 Message-ID: <11941.869599295@orion.webspan.net> Sender: owner-freebsd-isp@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk Dev Chanchani wrote in message ID : > Has anyone played with the following kernel option: > > pseudo-device ccd number I wouldn't say I've played with it, but I've got two machines in production using it :) > I was just wondering about experience in concatenating multiple disks. > (And does this option work with multiple disks, or just multiple > partitions within one disk)? Both ways, although the real win is multiple disks (with same-size paritions, or ideally, identical disks with identical layouts) as there can be some major performance gains. Note that not only can you use it for striping (i.e. chaining multiple physical partitions into one bigger logical partition) but you can also do mirroring. Unfortunately mirroring is not as guarenteed as it should be about data safety. I've had one disk in a 2 drive mirror die, and when the machine came back all the files that were on the still-alive drive were 0 length :-/ Gary -- Gary Palmer FreeBSD Core Team Member FreeBSD: Turning PC's into workstations. See http://www.FreeBSD.ORG/ for info