From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?iso-8859-1?Q?Jakob_=D8stergaard?= Subject: Re: RAID-6 support in kernel? Date: Wed, 5 Jun 2002 12:53:41 +0200 Sender: linux-raid-owner@vger.kernel.org Message-ID: <20020605125341.E31741@unthought.net> References: <1023125615.1051.1283.camel@peecee> <20020604222053.C31741@unthought.net> <20020605075701.GD2541@colombina.comedia.it> 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: <20020605075701.GD2541@colombina.comedia.it>; from bluca@comedia.it on Wed, Jun 05, 2002 at 09:57:01AM +0200 To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Wed, Jun 05, 2002 at 09:57:01AM +0200, Luca Berra wrote: > On Tue, Jun 04, 2002 at 10:20:53PM +0200, Jakob =D8stergaard wrote: > > What often happens (in my experience) is, that a number of disks bu= ild up bad > > blocks. One day, you hit one of those bad blocks, and that one dis= k is kicked > > from the array. > >=20 > > When you re-sync, you *will* hit the remaining bad blocks on the ot= her disks, > > causing the array to fail completely. > >=20 > > Using hot-spares will "automate" this failure - meaning that an adm= inistrator > > may not be anywhere near the system when this total failure happens= =2E > >=20 > > Not using hot-spares is less "automatic" in the lucky case where ev= erything > > works, but it also assures that an administrator actually is near t= he system > > when the total failure is likely to occur. > well, what we could do to prevent this. if you don't have or trust S.= M.A.R.T. I have and use SMART, and because of my experiences with it I do not tr= ust it :) > is having a 'consistency check' function in md, that would read from = all disks > and even compare data or calculate parity for raid5, it could be sche= duled > to run periodically with a very very low priority. This definitely belongs in user-space. But you are right, and I've dis= cussed it with colleagues before as well - it would be a good thing to have su= ch a tool. In root's crontab you could easily just put a 'dd if=3D/dev/hda of=3D/d= ev/null' and so on for all your drives. No need for kernel extensions here... --=20 =2E............................................................... : jakob@unthought.net : And I see the elder races, : :.........................: putrid forms of man : : Jakob =D8stergaard : See him rise and claim the earth, : : OZ9ABN : his downfall is at hand. : :.........................:............{Konkhra}...............: - 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