From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yh0-f42.google.com ([209.85.213.42]:41468 "EHLO mail-yh0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755058AbaLVQFl (ORCPT ); Mon, 22 Dec 2014 11:05:41 -0500 Received: by mail-yh0-f42.google.com with SMTP id v1so2414290yhn.1 for ; Mon, 22 Dec 2014 08:05:39 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: Date: Mon, 22 Dec 2014 09:05:39 -0700 Message-ID: Subject: Re: Uncorrectable errors on RAID-1? From: Chris Murphy To: constantine Cc: Chris Murphy , Btrfs BTRFS Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Mon, Dec 22, 2014 at 7:28 AM, constantine wrote: > On Mon, Dec 22, 2014 at 12:24 AM, Chris Murphy wrote: >> smartctl -l scterc /dev/sdX > > That's really good to know. My drives are desktop and this feature is > not supported; hence, I get "SCT Error Recovery Control command not > supported". > > I'll definitely go for enterprise/raid class drives that support this > command in the future; they somehow seem more transparent (if I may > say) in maintaining them. Not knowing anything else, I'd say the kernel command timer should be set to 121 in your case, for each drive. If you find evidence it can be shorter, go with that. Bad sectors will fast fast, which is what you want since you have mirrored data. Marginal sectors might take a while for the firmware to either recover, or fail. It's possible to mitigate long recoveries with a periodic balance, say once every six months. This rewrites all data, and all sectors ought to have a decently strong signal. Any sector with a persistent write problem is removed from use automatically by drive firmware, but this tends to require a write operation to trigger. -- Chris Murphy