From mboxrd@z Thu Jan 1 00:00:00 1970 From: Larkin Lowrey Subject: Re: Slow writing of dirty data (bcache) Date: Mon, 10 Mar 2014 16:14:41 -0500 Message-ID: <531E2B41.5030605@nuclearwinter.com> References: <531DE9A5.90801@nuclearwinter.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from titan.nuclearwinter.com ([174.136.96.186]:51436 "EHLO mail.nuclearwinter.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751231AbaCJVOn (ORCPT ); Mon, 10 Mar 2014 17:14:43 -0400 In-Reply-To: Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Kent Overstreet Cc: linux-bcache@vger.kernel.org This solved my immediate problem. Thank you very much. Should I keep this array at 0 from now on if I want it to spin down when idle? --Larkin On 3/10/2014 12:12 PM, Kent Overstreet wrote: > > echo 0 > writeback_percent... > > On Mar 10, 2014 6:07 PM, "Larkin Lowrey" > wrote: > > I'm seeing an odd behavior after updating to kernel > 3.13.5-202.fc20.x86_64 from 3.12.7-300.fc20.x86_64. > > I have a bcache device (bcache2) which backs a raid5 array (md2) that > has 160+MB of dirty data. The dirty data is being written at a > rate of 1 > page per second (8 sectors). At this rate it'll take 11 hrs to > finish. I > like to keep this array spun down when inactive but the drives can't > spin down since they're being written to once a second. > > # cat /sys/block/bcache2/bcache/writeback_rate > 512 > > # cat /sys/block/bcache2/bcache/writeback_rate_debug > rate: 512/sec > dirty: 161M > target: 40.8G > proportional: -35.2M > derivative: 0 > change: -35.2M/sec > next io: 624ms > > This never happened when running 3.12.7. Is there anything I can do > about this? > > --Larkin > > > -- > To unsubscribe from this list: send the line "unsubscribe > linux-bcache" in > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html >