From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roman Mamedov Subject: Re: RAID 1 not fixing up sector errors? Date: Fri, 15 Apr 2016 12:56:32 +0500 Message-ID: <20160415125632.099c1fbd@natsu> References: <29813347.d6oRyCVBGp@dag.newtech.fi> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/2R.xS.VgZEe+_NrLmFOEHAT"; protocol="application/pgp-signature" Return-path: In-Reply-To: <29813347.d6oRyCVBGp@dag.newtech.fi> Sender: linux-raid-owner@vger.kernel.org To: Dag Nygren Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/2R.xS.VgZEe+_NrLmFOEHAT Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Thu, 14 Apr 2016 16:03:59 +0300 Dag Nygren wrote: > Hi! >=20 > Have set up a RAID1 here for temporary storage of some backup files. > As I am using Seagate barracudas I am prepared for sector errors :-). > that's why I am using RAID1. >=20 > Anyway I do get those occasional "Pending Reallocate" with > the appropriate corresponding > Unrecovered read error - auto reallocate failed > in the log. >=20 > A resync of the array will rewrite the failing sector=20 > and the drive seems to reallocate it and all is fine again . >=20 > But I was expecting the MD layer to try to fixup that sector > automatically by using the data from the other drive ?? >=20 > Is there something I need to explicitly enable? > Or am I expecting too much ;-) I have seen this behavior too. The only somewhat logical explanation that I have, is that some drives are only able to remap bad sectors if a larger ar= ea around the sector is overwritten, and not just the sector itself. But this = is not scientific or verified. --=20 With respect, Roman --Sig_/2R.xS.VgZEe+_NrLmFOEHAT Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAlcQnr8ACgkQTLKSvz+PZwjv6ACfXb4aGwNcDvZYuzaGSwUH5zlj 61sAn1+vLcHXDfB+S0mLkkWndHIYbop9 =flTT -----END PGP SIGNATURE----- --Sig_/2R.xS.VgZEe+_NrLmFOEHAT--