From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: Problem re-shaping RAID6 Date: Thu, 17 Jun 2010 15:47:08 +1000 Message-ID: <20100617154708.227cd303@notabene.brown> References: <20100614091518.2492a9db@notabene.brown> <20100614124723.84152dz5al8096f4@cakebox.homeunix.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20100614124723.84152dz5al8096f4@cakebox.homeunix.net> Sender: linux-raid-owner@vger.kernel.org To: Nagilum Cc: linux-raid List-Id: linux-raid.ids On Mon, 14 Jun 2010 12:47:23 +0200 Nagilum wrote: >=20 > ----- Message from neilb@suse.de --------- > Date: Mon, 14 Jun 2010 09:15:18 +1000 > From: Neil Brown > Subject: Re: Problem re-shaping RAID6 > To: J=C3=A9r=C3=B4me Poulin > Cc: linux-raid >=20 >=20 > > Thanks. > > I fixed this bug a slightly different way > > > > - blocks =3D ochunk/512 * nchunk/512 * odata * ndata = / a; > > + blocks =3D (ochunk/512) * (nchunk/512) * odata * nd= ata / a; > > > > > > See > > http://neil.brown.name/git?p=3Dmdadm;a=3Dcommitdiff;h=3D200871adf9e= 15d5ad985f28c349fd89c386ef48a >=20 > Those static numbers always make my nose wrinkle. > Don't we have the blocksize somewhere already? I'm also concerned wha= t =20 > happens when true 4k sectors are used.. >=20 A sector will always be 512 bytes to Linux, even when we have drives th= at can only do IO in multiples of 8 sectors. Changing that would cause way to= many headaches. Yes, I could possibly use a define for '512'. Some times that is appropriate, but I thing 512 is so clearly "bytes_per_sector" it would = just add an unnecessary level of indirection. It is a question of taste really - no right answers. Thanks, NeilBrown -- 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