From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:46901 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751319AbbFREiV (ORCPT ); Thu, 18 Jun 2015 00:38:21 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1Z5Raj-0006Dp-Hi for linux-btrfs@vger.kernel.org; Thu, 18 Jun 2015 06:38:17 +0200 Received: from ip68-231-22-224.ph.ph.cox.net ([68.231.22.224]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 18 Jun 2015 06:38:17 +0200 Received: from 1i5t5.duncan by ip68-231-22-224.ph.ph.cox.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 18 Jun 2015 06:38:17 +0200 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: RAID10 Balancing Request for Comments and Advices Date: Thu, 18 Jun 2015 04:37:54 +0000 (UTC) Message-ID: References: <1434456557.89597618@apps.rackspace.com> <20150616122545.GI9850@carfax.org.uk> <61CBE6C4-0D06-4F16-B522-4DBB756FBC31@up4.com> <80BA2964-3B67-430B-99BE-62A348C5DBED@up4.com> <20150617132736.GT9850@carfax.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hugo Mills posted on Wed, 17 Jun 2015 13:27:36 +0000 as excerpted: >> Yes, on this 80% full 6x4TB RAID10 -dusage=15 took 2 seconds and >> relocated "0 out of 3026 chunks”. >> >> Out of curiosity, I had to use -dusage=90 to have it relocate only 1 >> chunk and it took les than 30 seconds. >> >> So I put a -dusage=25 in the weekly cron just before the scrub. > > In most cases, all you need to do is clean up one data chunk to > give the metadata enough space to work in. Instead of manually iterating > through several values of usage= until you get a useful response, you > can use limit= to stop after successful block group relocations. Thanks, Hugo. It wasn't previously clear to me what the practical usage for the (relatively new) limit= filter was. Very useful explanation. =:^) -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman