From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keld =?iso-8859-1?Q?J=F8rn?= Simonsen Subject: Re: Has anyone compared SWRAID for (JBOD@HW-RAID) vs. (Regular Sata PCI-e cards)? Date: Sun, 11 May 2008 09:39:36 +0200 Message-ID: <20080511073936.GB20335@rap.rap.dk> References: <181601c8b2a7$12fe0489$5209f40a@exchange.rackspace.com> <4825D7DA.2050608@garzik.org> <20080510222817.GA26706@rap.rap.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <20080510222817.GA26706@rap.rap.dk> Sender: linux-raid-owner@vger.kernel.org To: Jeff Garzik Cc: Justin Piszcz , David Lethe , linux-raid@vger.kernel.org List-Id: linux-raid.ids On Sun, May 11, 2008 at 12:28:17AM +0200, Keld J=F8rn Simonsen wrote: > On Sat, May 10, 2008 at 01:14:02PM -0400, Jeff Garzik wrote: > >=20 > > And of course, there are plenty of other factors to consider. I wr= ote a=20 > > bit on this topic at http://linux.yyz.us/why-software-raid.html >=20 > So that is you writing this page! I think it is one of the more usefu= l > pages on raid (many others are quite outdated).=20 >=20 > I have a suggestion for an advantage for SW raid, that you could > consider for your page: >=20 > - potential for increased performance, due to more intelligent layout= s, > for example the linux raid10,f2 has more than double the performanc= e > for both sequential reads and random reads compared to most hardwar= e > RAID1, and Linux SW RAID1. >=20 > - potential for better error handling, due to more intelligent driver= s. > Linux raid10 has better error handling than linux RAID1 and possibl= y > also HW RAID1. >=20 > And then, if you could link to our HOWTO pages at > http://linux-raid.osdl.org/ that would improve the visibility for our > pages. It seems like not many are referencing our pages, so if people= on > this list would make a link to http://linux-raid.osdl.org/ that would > increase the chance of our information to be seen. >=20 > Best regards > keld Another advantage of SW raid: - SW RAID is more flexible. On a set of drives you can with SW RAID mix different types of raid, for example the /boot partition could be RAID1 so that it can be booted by grub/lilo, the / partition could be= =20 raid10,f2 for greater read performance, and the data partition could = be=20 raid5 to get more effective space out of your drives. In HW RAID you = can only allocate whole disks to one RAID type. best regards Keld -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html