From mboxrd@z Thu Jan 1 00:00:00 1970 From: adfas asd Subject: Re: Remote NAS Date: Wed, 23 Sep 2009 15:58:41 -0700 (PDT) Message-ID: <117705.89087.qm@web38807.mail.mud.yahoo.com> References: <20090923210145.GA23285@rap.rap.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20090923210145.GA23285@rap.rap.dk> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids --- On Wed, 9/23/09, Keld J=F8rn Simonsen wrote: > Writes are about the same for RAID10 types and RAID1. > This is also what theory would tell for random writes, > given that they > are random, and that the elevator algorithm of the file > system optimizes > the writing.=20 >=20 > Yes, offset came after far, but Neil Brown said that offset > was > implemented to make Linux MD align to RAID standards. It > was not > necessarily meant to be better than far.=20 >=20 > I think it is hard to beat raid10 far on reads (but then I > am also the > one that invented the layout). As said for random reading > and writing > the theory says that all mirrored raid types perform > equally, and tests > verify this. Maybe far layout even has an edge for random > reading, in > theory it should, but I have not seen tests really > verifying that. Excellent, thanks Keld. =20 -- 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