From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keld =?iso-8859-1?Q?J=F8rn?= Simonsen Subject: Re: What's the typical RAID10 setup? Date: Fri, 4 Feb 2011 23:05:07 +0100 Message-ID: <20110204220507.GA6876@www2.open-std.org> References: <4D475AB5.10600@hardwarefreak.com> <20110203110428.GA26762@www2.open-std.org> <4D4B3DAE.3070502@hardwarefreak.com> <20110204070613.GA3788@www2.open-std.org> <4D4BB87A.30800@hardwarefreak.com> <20110204090602.GA4017@www2.open-std.org> <20110204204251.GB6603@www2.open-std.org> <4D4C6C7B.2020304@hardwarefreak.com> 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: <4D4C6C7B.2020304@hardwarefreak.com> Sender: linux-raid-owner@vger.kernel.org To: Stan Hoeppner Cc: Keld =?iso-8859-1?Q?J=F8rn?= Simonsen , Jon Nelson , Mathias =?iso-8859-1?Q?Bur=E9n?= , Roberto Spadim , Denis , Linux-RAID List-Id: linux-raid.ids On Fri, Feb 04, 2011 at 03:15:39PM -0600, Stan Hoeppner wrote: > Keld J=F8rn Simonsen put forth on 2/4/2011 2:42 PM: >=20 > >>> So apparently their Disk Data Format specification doesn't includ= e hybrid RAID > >>> levels. This makes sense, as the _on disk_ layout of RAID 10 is = identical to > >>> RAID 1. > >=20 > > I was puzzled here. I think you mean: > >=20 > > "the _on disk_ layout of RAID 10 is identical to RAID 1 and RAID 0" > >=20 > > If that is what you meant, I think we agree on most things here. >=20 > I set a trap for you, of sorts. ;) And I deliberately fell into your trap, tongue in cheek:-) Maybe we should avoid traps and fooling around in them, as it just confuses others and waistes our time. I do think there are valid points coming out of our discussion here. I have tried to avoid your ad hominem remarks and traps, and just try to be constructive. > If what you say is true, then RAID 10 should > be covered in the DDF, as migration from one device to another isn't = possible > without the RAID 10 on disk layout being defined in the DDF as with a= ll the > other RAID levels. True? I am a little puzzled with what you mean here. RAID 1+0 is covered in DDF 2.0 as a description of RAID-1 or RAID-1E , and then striping it according to 4.3.1 . I do think they should add something about calling it RAID 1+0 or maybe RAID-1E+0 or some such. And then explain something about the term "RAID10" and why you should rather call it RAID-1+0 or RAID-1E+0, to indicate it is a Secondary RAID level, and to avoid ambiguity.=20 I have given some remarks on RAID10 on=20 http://www.snia.org/tech_activities/feedback/ 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