Date: Sat, 5 May 2001 23:03:05 -0400 From: "Jonathan Fortin" <jfortin@akalink.com> To: "Bob Greene" <rgreene@tclme.org> Cc: <questions@freebsd.org> Subject: Re: Raid Message-ID: <003c01c0d5d9$12698a60$020a10ac@node00> References: <000a01c0d57f$2158bb40$0400a8c0@192.168.0.1> <000701c0d581$3dd2da60$0e00000a@tomcat> <20010506101618.B39554@wantadilla.lemis.com> <3AF4BF5A.A03D7278@tclme.org>
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I would prefer using raid 0+1 also known as raid 10. you will have 2 striped sets, hd1+hd2 <-> hd3-h4 then both strips will be mirrored. Say you got 4 36gb hds, you can have a redundant 72gb slice without raid1's performance hit at the extra cost of disks. ----- Original Message ----- From: "Bob Greene" <rgreene@tclme.org> To: "Greg Lehey" <grog@lemis.com> Cc: "Andrew C. Hornback" <hornback@wireco.net>; "Steve Blanzy" <sblanzy@aperion.com>; "FreeBSD Questions" <questions@FreeBSD.ORG> Sent: Saturday, May 05, 2001 11:04 PM Subject: Re: Raid > Greg Lehey wrote: > > > > No, RAID-1 gives you the best performance of any RAID setup. The > > reason why you need at least 3 disks for RAID-5 is because it is > > slower, and though it would theoretically work with only two disks, > > it has no advantages over RAID-1 in this configuration. > > > > Huh? This paragraph makes no sense. > > RAID 0 = striped set > RAID 1 = mirrored set > RAID 5 = striped set with parity > > RAID 1 gives maximum redundancy, at the cost of two writes. The third > disk in RAID 5 is not a consequence of performance, it's a requirement > for redundancy. RAID 5 with only 2 disks is a failure condition of a 3 > disk array. At that point it's effectively just a striped set. > > -- > Bob Greene > rgreene@TclMe.org > Pull my finger for my public key > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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