From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from torres.zugschlus.de ([85.214.131.164]:39508 "EHLO torres.zugschlus.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754090AbcCOOJJ (ORCPT ); Tue, 15 Mar 2016 10:09:09 -0400 Received: from mh by torres.zugschlus.de with local (Exim 4.84) (envelope-from ) id 1afpel-0003Ev-66 for linux-btrfs@vger.kernel.org; Tue, 15 Mar 2016 15:09:07 +0100 Date: Tue, 15 Mar 2016 15:09:07 +0100 From: Marc Haber To: Btrfs BTRFS Subject: Re: New file system with same issue Message-ID: <20160315140907.GT2334@torres.zugschlus.de> References: <20160305143934.GE1902@torres.zugschlus.de> <20160313115809.GQ2334@torres.zugschlus.de> <20160314120703.GD2334@torres.zugschlus.de> <56E6B312.30903@googlemail.com> <20160314201306.GH2334@torres.zugschlus.de> <56E7E96E.6080301@googlemail.com> <20160315134602.GQ2334@torres.zugschlus.de> <56E813FE.2070206@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <56E813FE.2070206@gmail.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Tue, Mar 15, 2016 at 09:54:06AM -0400, Austin S. Hemmelgarn wrote: > On 2016-03-15 09:46, Marc Haber wrote: > >On Tue, Mar 15, 2016 at 11:52:30AM +0100, Holger Hoffstätte wrote: > >>On 03/14/16 21:13, Marc Haber wrote: > >>>Do I need to wait for clear_cache to finish, like until I see disk > >>>usage dropping? > >> > >>The cache isn't that big, so you won't see a huge drop. Just use the > >>disk normally for a few minutes, after some time the cache will be > >>written out again. > > > >Is it necessary to actually cause activity on the file system or is it > >ok to just let it sit there for an hour or so? > It should be OK to just let it sit there for ten or fifteen minutes. I'm > pretty certain that the free space cache gets rebuilt relatively quickly, > and I'm almost 100% certain that the old one gets dropped within seconds of > the FS being mounted with -o clear_cache. I've rebuilt the cache on the 64G > root filesystem on my laptop a couple of times before, and it consistently > appears to take about 2-3 minutes to do so at most (based on disk usage from > the kernel itself). In my case, atop has not seen any notable disk activity after mounting with -o clerar_cache. Greetings Marc -- ----------------------------------------------------------------------------- Marc Haber | "I don't trust Computers. They | Mailadresse im Header Leimen, Germany | lose things." Winona Ryder | Fon: *49 6224 1600402 Nordisch by Nature | How to make an American Quilt | Fax: *49 6224 1600421