From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Masover Subject: Re: the " 'official' point of view" expressed by kernelnewbies.org regarding reiser4 inclusion Date: Tue, 01 Aug 2006 12:41:59 -0500 Message-ID: <44CF9267.7050202@slaphack.com> References: <200607312314.37863.bernd-schubert@gmx.de> <200608011428.k71ESIuv007094@laptop13.inf.utfsm.cl> <20060801165234.9448cb6f.reiser4@blinkenlights.ch> <1154446189.15540.43.camel@localhost.localdomain> <44CF84F0.8080303@slaphack.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Gregory Maxwell Cc: Alan Cox , Adrian Ulrich , "Horst H. von Brand" , bernd-schubert@gmx.de, reiserfs-list@namesys.com, jbglaw@lug-owl.de, clay.barnes@gmail.com, rudy@edsons.demon.nl, ipso@snappymail.ca, reiser@namesys.com, lkml@lpbproductions.com, jeff@garzik.org, tytso@mit.edu, linux-kernel@vger.kernel.org Gregory Maxwell wrote: > On 8/1/06, David Masover wrote: >> Yikes. Undetected. >> >> Wait, what? Disks, at least, would be protected by RAID. Are you >> telling me RAID won't detect such an error? > > Unless the disk ECC catches it raid won't know anything is wrong. > > This is why ZFS offers block checksums... it can then try all the > permutations of raid regens to find a solution which gives the right > checksum. Isn't there a way to do this at the block layer? Something in device-mapper? > Every level of the system must be paranoid and take measure to avoid > corruption if the system is to avoid it... it's a tough problem. It > seems that the ZFS folks have addressed this challenge by building as > much of what is classically separate layers into one part. Sounds like bad design to me, and I can point to the antipattern, but what do I know?