From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Lord Subject: Re: SATA hdd refuses to reallocate a sector? Date: Mon, 24 Jun 2013 08:18:15 -0400 Message-ID: <51C83907.2020202@pobox.com> References: <20130623101940.GA4448@amd.pavel.ucw.cz> <51C76858.4060906@pobox.com> <20130623215100.GA7414@amd.pavel.ucw.cz> <201306240914.29502.linux@rainbow-software.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from a-pb-sasl-quonix.pobox.com ([208.72.237.25]:43607 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752426Ab3FXMSe (ORCPT ); Mon, 24 Jun 2013 08:18:34 -0400 In-Reply-To: <201306240914.29502.linux@rainbow-software.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Ondrej Zary Cc: Pavel Machek , Marcus Overhagen , kernel list , linux-ide@vger.kernel.org, tj@kernel.org On 13-06-24 03:14 AM, Ondrej Zary wrote: .. > Being tired of using hdparm manually, I created a simple hdd_realloc utility > that reads the disk in big blocks (1 MB). When there's a read error, it reads > the failed block sector-by-sector and tries to rewrite the sectors that fail > to read. It work fine for disks with just a couple of pending sectors. Something like that would work very well if it used the hdparm approach (directly to the drive) for the sector-by-sector part. Going through the block layer isn't always going to work, because the kernel likes to do I/O in PAGE_SIZE multiples. And the SCSI stack in Linux has rather atrocious error handling. It lumps multiple requests together, and can fail the entire lot even if only a single sector is bad. Cheers -- Mark Lord Real-Time Remedies Inc. mlord@pobox.com