Received: from localhost (maia-3.hub.org [200.46.204.184]) by postgresql.org (Postfix) with ESMTP id 720F89FB874 for ; Wed, 30 May 2007 12:57:41 -0300 (ADT) Received: from postgresql.org ([200.46.204.71]) by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024) with ESMTP id 39960-07 for ; Wed, 30 May 2007 12:57:34 -0300 (ADT) X-Greylist: from auto-whitelisted by SQLgrey-1.7.5 Received: from mail.envysolutions.com (unknown [206.248.142.186]) by postgresql.org (Postfix) with ESMTP id 543259FB32F for ; Wed, 30 May 2007 12:57:35 -0300 (ADT) Received: from localhost (localhost.localdomain [127.0.0.1]) by mail.envysolutions.com (Postfix) with ESMTP id 347EC5404E; Wed, 30 May 2007 11:57:34 -0400 (EDT) X-Virus-Scanned: amavisd-new at mail.envysolutions.com Received: from mail.envysolutions.com ([127.0.0.1]) by localhost (mark.mielke.cc [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id pN9F3PtaNUlJ; Wed, 30 May 2007 11:57:34 -0400 (EDT) Received: by mail.envysolutions.com (Postfix, from userid 500) id 0991E5404F; Wed, 30 May 2007 11:57:34 -0400 (EDT) Date: Wed, 30 May 2007 11:57:34 -0400 From: mark@mark.mielke.cc To: Luke Lonergan Cc: Michael Stone , pgsql-performance@postgresql.org Subject: Re: setting up raid10 with more than 4 drives Message-ID: <20070530155733.GA18830@mark.mielke.cc> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.2i X-Virus-Scanned: Maia Mailguard 1.0.1 X-Spam-Status: No, hits=0.84 tagged_above=0 required=5 tests=AWL=-0.257, BAYES_50=0.001, FORGED_RCVD_HELO=0.135, NO_REAL_NAME=0.961 X-Spam-Level: X-Archive-Number: 200705/621 X-Sequence-Number: 25011 On Wed, May 30, 2007 at 08:51:45AM -0700, Luke Lonergan wrote: > > This is standard stuff, very well proven: try googling 'self healing zfs'. > The first hit on this search is a demo of ZFS detecting corruption of one of > the mirror pair using checksums, very cool: > > http://www.opensolaris.org/os/community/zfs/demos/selfheal/;jsessionid=52508 > D464883F194061E341F58F4E7E1 > > The bad drive is pointed out directly using the checksum and the data > integrity is preserved. One part is corruption. Another is ordering and consistency. ZFS represents both RAID-style storage *and* journal-style file system. I imagine consistency and ordering is handled through journalling. Cheers, mark -- mark@mielke.cc / markm@ncf.ca / markm@nortel.com __________________________ . . _ ._ . . .__ . . ._. .__ . . . .__ | Neighbourhood Coder |\/| |_| |_| |/ |_ |\/| | |_ | |/ |_ | | | | | | \ | \ |__ . | | .|. |__ |__ | \ |__ | Ottawa, Ontario, Canada One ring to rule them all, one ring to find them, one ring to bring them all and in the darkness bind them... http://mark.mielke.cc/