From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from james.kirk.hungrycats.org ([174.142.39.145]:40041 "EHLO james.kirk.hungrycats.org" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1754691AbaLWVQ4 (ORCPT ); Tue, 23 Dec 2014 16:16:56 -0500 Date: Tue, 23 Dec 2014 16:16:09 -0500 From: Zygo Blaxell To: Chris Murphy Cc: Btrfs BTRFS Subject: Re: Uncorrectable errors on RAID-1? Message-ID: <20141223211605.GC436@hungrycats.org> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="6zdv2QT/q3FMhpsV" In-Reply-To: Sender: linux-btrfs-owner@vger.kernel.org List-ID: --6zdv2QT/q3FMhpsV Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sun, Dec 21, 2014 at 05:25:47PM -0700, Chris Murphy wrote: > For the kernel to automatically fix > bad sectors by overwriting them, the drive needs to explicitly report > read errors. If the SCSI command timer value is shorter than the > drive's error recovery, the SATA link might get reset before the drive > reports the read error and then uncorrected errors will persist > instead of being automatically fixed. Is there a way to tell the kernel to go ahead and assume that all timeouts are effectively read errors? For a simple non-removable hard disk (i.e. not removable and not optical), that seems like a reasonable workaround for an assortment of firmware brokenness. I just did a quick survey of random drives here and found less than 10% support "smartctl -l scterc". A lot of server drives (or at least the drives that shipped in servers) don't have it, but laptop drives do. Drives with firmware that has horrifying known bugs do also have this feature. :-P --6zdv2QT/q3FMhpsV Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlSZ25MACgkQgfmLGlazG5xitgCgtpaj3QcJWSEVXxJPaVIWtVnH 4OQAnA7cQfEIrfvOkpoLxQxdYMKWasYI =NIAP -----END PGP SIGNATURE----- --6zdv2QT/q3FMhpsV--