From mboxrd@z Thu Jan 1 00:00:00 1970 From: Derek Piper Subject: RAID5 on different sized disks on low-end machine Date: Tue, 11 Jan 2005 14:24:55 -0500 Message-ID: References: <200501112010.05469.maarten@ultratux.net> Reply-To: Derek Piper Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Wow, you replied so quick to my first posting already, thanks Maarten! :) On Tue, 11 Jan 2005 20:10:05 +0100, Maarten wrote: > On Tuesday 11 January 2005 19:47, Derek Piper wrote: > > > My question is this, is it possible (and even a good idea) to use all > > 4 hard drives as members of a 4 x 60GB RAID5 array by leaving 20GB of > > the 80GB drive as a non-raided partition? I'll be using a Promise > > Ultra TX2/100 controller. > > That's perfectly okay. Thank you, good to know. My plan kinda hinges on that. :) > > > i.e. RAID5 = 180GB usable size,wherease RAID6 = 120GB .. am I correct > > in my thinking? > > Yes. Thanks, I've only just started looking at what RAID6 offers. For bigger arrays than mine I think. > > I know many of you use far larger hard drives, I'm just trying to use > > the components I already had spare from a number of machines and > > reorganize to a RAID-backed fileserver. > > My first raid was a raid-0 from two 4.5 GB scsi disks... > My first raid at home was on 4x40GB drives, raid5. > > > The machine is a dual pentium-pro 200 (320MB RAM) .. would that be a > > dumb idea to use RAID5 on it because of the parity calculations > > needed? > > That raid-5 array above ran on a K6-300... may not be fast but you can almost > be sure that a 100Mbit ethernet is still slower... Okay, that's good to hear.. thank you :) > > Further to that, would it be a smarter idea to use RAID1 on all 4 of > > some small partition(s) at the start of the disks to house > > boot/root/usr partitions, and only RAID5 on a larger 'data' area of > > the drive that is more likely to be read than written to? > > YES ! If only because it is very hard to boot from raid-5. > But you could use that spare 20GB for the OS, couldn't you ? > Unless you want that redundant too. Ah, that's a good point about booting. Yea, I'd want to be able to get back running as simply as possible if a disk failure happens. The extra 20GB I was thinking I could use for something un-important, like downloads, temporary 'scratch' space etc. Maybe squid cache. Thanks for getting back with me so quick. Nice to bounce ideas off people. Derek -- Derek Piper - derek.piper@gmail.com http://doofer.org/