From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from nm31.bullet.mail.gq1.yahoo.com ([98.136.217.14]:26352 "HELO nm31.bullet.mail.gq1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751777Ab2JANe4 (ORCPT ); Mon, 1 Oct 2012 09:34:56 -0400 Message-ID: <50699A40.2030603@yahoo.com.br> Date: Mon, 01 Oct 2012 10:27:28 -0300 From: Cesar Inacio Martins MIME-Version: 1.0 To: linux-btrfs@vger.kernel.org Subject: Tunning - cache write (database) References: <1349098002.208.YahooMailNeo@web31801.mail.mud.yahoo.com> In-Reply-To: <1349098002.208.YahooMailNeo@web31801.mail.mud.yahoo.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi, First, sorry if this isn't the place to get this kind of help... If not, I appreciate some link , forum, where I can try get some answers... My problem: * Using btrfs + compression , flush of 60 MB/s take 4 minutes.... (on this 4 minutes they keep constatly I/O of +- 4MB/s no disks) (flush from Informix database) The enviroment : * Virtualized environment * OpenSuse 12.1 64bits, running over VmWare ESXi 5 * Btrfs version : btrfsprogs-0.19-43.1.2.x86_64 * Kernel : Linux jdivm06 3.1.10-1.16-desktop #1 SMP PREEMPT Wed Jun 27 05:21:40 UTC 2012 (d016078) x86_64 x86_64 x86_64 GNU/Linux * The file system is used to keep the Informix database data (chunks). * 8 cores (intel i7) , so, all btrfs threads able to work parallel. The file system mount : root@jdivm06:/proc/sys/fs# mount |grep ifx /dev/sdb1 on /ifxdados type btrfs (rw,nosuid,nodev,noexec,noatime,compress=zlib,space_cache) My question, what I believed will help to avoid this long flush : * Have some way to force this flush all in memory cache and then use the btrfs background process to flush to disk ... Security and recover aren't a priority for now, because this is part of a database bulkload ...after finish , integrity will be desirable (not a obligation, since this is a test environment) For now, performance is the mainly requirement... A plus : root@jdivm06:/proc/sys/fs# cat /proc/sys/vm/dirty_ratio 50 root@jdivm06:/proc/sys/fs# cat /proc/sys/vm/dirty_background_ratio 10 Thanks Cesar