From owner-cvs-all Thu Jul 5 14:53:30 2001 Delivered-To: cvs-all@freebsd.org Received: from peter3.wemm.org (c1315225-a.plstn1.sfba.home.com [65.0.135.147]) by hub.freebsd.org (Postfix) with ESMTP id 8E8B137B409; Thu, 5 Jul 2001 14:53:24 -0700 (PDT) (envelope-from peter@wemm.org) Received: from overcee.netplex.com.au (overcee.wemm.org [10.0.0.3]) by peter3.wemm.org (8.11.0/8.11.0) with ESMTP id f65LrOM65015; Thu, 5 Jul 2001 14:53:24 -0700 (PDT) (envelope-from peter@wemm.org) Received: from wemm.org (localhost [127.0.0.1]) by overcee.netplex.com.au (Postfix) with ESMTP id 448BA3809; Thu, 5 Jul 2001 14:53:24 -0700 (PDT) (envelope-from peter@wemm.org) X-Mailer: exmh version 2.3.1 01/18/2001 with nmh-1.0.4 To: Poul-Henning Kamp Cc: Ben Smithurst , cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/etc diskcheckd.conf In-Reply-To: <6446.994361127@critter> Date: Thu, 05 Jul 2001 14:53:24 -0700 From: Peter Wemm Message-Id: <20010705215324.448BA3809@overcee.netplex.com.au> Sender: owner-cvs-all@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG Poul-Henning Kamp wrote: > In message <20010705151553.E97328@strontium.shef.vinosystems.com>, Ben Smithu rs > t writes: > > >I'm tempted to think the default diskcheckd.conf shouldn't check > >anything, checking everything by default seems to be causing trouble. > > > >Poul-Henning, what's your view? > > How about checking all disks which: > are larger than 1G and do not contain "cd" in their name ? > as default ? For what its worth, I have yet to see a modern drive that does do scrubbing of marginal data. Ie: a soft error (ecc correctable) does not cause a writeback that I have ever seen. I have a really revolting program that I wrote years ago that did bad block scanning and scrubbing in userland. I had an opportunity to use it a few months ago on a disk that had got too hot and was getting lots of retries and ECC corrections. (ie: it was really really slow at reading). I used the 'rewrite' option in my hack program, which reads into a large buffer and rewrites a few megabytes behind. The problems went away and it resumed full speed. (This was a quantum 30G ATA disk). I wrote the program for scsi disks years ago, and I certainly recall similar behavior there too - which is why I even added the rewrite option to the scanner. I am not sure that the basic assumption behind diskcheckd is valid.. Is there any way to verify for sure that marginal sector scrubbing really happens on at least some drives? Cheers, -Peter -- Peter Wemm - peter@FreeBSD.org; peter@yahoo-inc.com; peter@netplex.com.au "All of this is for nothing if we don't go to the stars" - JMS/B5 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message