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From: Colonel Hell <amritanshu@gmail.com>
To: dean gaudet <dean-list-linux-raid@arctic.org>
Cc: linux-raid@vger.kernel.org
Subject: Re: RAID6 Query
Date: Wed, 17 Aug 2005 00:44:52 +0800	[thread overview]
Message-ID: <4ecc821305081609443247f5d5@mail.gmail.com> (raw)
In-Reply-To: <Pine.LNX.4.63.0508160838300.20705@twinlark.arctic.org>

thanks and sorry for a stupid qry suffering from foot-in-the-mouth disease :P

On 8/16/05, dean gaudet <dean-list-linux-raid@arctic.org> wrote:
> On Tue, 16 Aug 2005, Colonel Hell wrote:
> 
> > I just went thru a couple of papers describing RAID6.
> > I dunno how relevant this discussion grp is for the qry ...but here I go :) ...
> > I couldnt figure out why is P+Q configuration better over P+q' where
> > q' == P. What I mean is instead of calculating a new checksum (thru a
> > lot of GF theory etc) just store the parity block (P)again. In this
> > case as well we have the same amount of fault tolerance or not
> > :-s  ...
> 
> this is no better than raid5 at surviving a two disk failure.  i.e.
> consider the case of two data blocks missing -- you can't reconstruct if
> all you have is parity.
> 
> -dean
>

  reply	other threads:[~2005-08-16 16:44 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20050717182650.24540.patches@notabene>
2005-07-17  8:27 ` [PATCH md ] When resizing an array, we need to update resync_max_sectors as well as size NeilBrown
2005-07-17 12:10   ` Found a new bug! djani22
2005-07-17 22:13     ` Neil Brown
2005-07-17 22:31       ` djani22
2005-08-14 22:38       ` djani22
2005-08-15  1:21         ` Neil Brown
2005-08-15 10:50           ` djani22
2005-08-16 13:54             ` perfomance question djani22
2005-08-16 14:30               ` RAID6 Query Colonel Hell
2005-08-16 15:40                 ` dean gaudet
2005-08-16 16:44                   ` Colonel Hell [this message]
2005-08-18  4:59               ` perfomance question Neil Brown
2005-08-18 15:20                 ` djani22
2005-08-18  4:34             ` Found a new bug! Neil Brown
2005-08-18 15:39               ` djani22
2005-08-20  9:55                 ` Oops in raid1? djani22
2005-08-20 15:53                   ` Pallai Roland
2005-08-20 16:26                     ` djani22
2005-08-20 16:50                       ` Pallai Roland
2005-08-20 16:57                         ` djani22

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