From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adam Kropelin Subject: Re: Linux: Why software RAID? Date: Thu, 24 Aug 2006 09:07:41 -0400 Message-ID: <20060824090741.J30362@mail.kroptech.com> References: <44ED1E41.40606@garzik.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <44ED1E41.40606@garzik.org> Sender: linux-raid-owner@vger.kernel.org To: Jeff Garzik Cc: Linux Kernel , Linux RAID Mailing List , marc@perkel.com List-Id: linux-raid.ids Jeff Garzik wrote: > But anyway, to help answer the question of hardware vs. software RAID, I > wrote up a page: > > http://linux.yyz.us/why-software-raid.html > > Generally, you want software RAID unless your PCI bus (or more rarely, > your CPU) is getting saturated. With RAID-0, there is no duplication of > data, and so, PCI bus and CPU usage should be about the same for > hardware and software RAID. Hardware RAID can be (!= is) more tolerant of serious drive failures where a single drive locks up the bus. A high-end hardware RAID card may be designed with independent controllers so a single drive failure cannot take other spindles down with it. The same can be accomplished with sw RAID of course if the builder is careful to use multiple PCI cards, etc. Sw RAID over your motherboard's onboard controllers leaves you vulnerable. --Adam