From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Subject: Change size journal's blocks from 4k to another. Date: Tue, 13 May 2014 11:22:26 +0400 Message-ID: <5371C832.70406@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-lb0-f182.google.com ([209.85.217.182]:43735 "EHLO mail-lb0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753172AbaEMHWa (ORCPT ); Tue, 13 May 2014 03:22:30 -0400 Received: by mail-lb0-f182.google.com with SMTP id q8so8316000lbi.13 for ; Tue, 13 May 2014 00:22:29 -0700 (PDT) Received: from localhost.localdomain ([212.34.43.122]) by mx.google.com with ESMTPSA id o1sm2639438lbw.27.2014.05.13.00.22.27 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 13 May 2014 00:22:28 -0700 (PDT) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org Hello. I am also sent this message to ceph-users@ maillist, but nobody answer me. If this topic is inappropriate for this maillist I am already to apologize. In my Ceph installation I am uses a ssd drive for journal with direct access. When an osd started I see in log file this string: ... 1 journal _open /dev/sda1 fd 22: 19327352832 bytes, block size 4096 bytes, directio = 1, aio = 1 ... How I can change size of block from 4k to 512k, because my SSD show better perfomance witch large blocks: * With 4K (sdr6 - source, sda8 - target) dd if=/mnt/from/random of=/mnt/sda8/random bs=4k oflag=direct,dsync iostat show me the statistic: iostat -cdm 1 /dev/sda /dev/sdr Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 16198.00 0.00 126.54 0 126 sdr 126.00 15.75 0.00 15 0 * With 512K (sdr6 - source, sda8 - target) Sync: sync Clear cache: echo 1 > /proc/sys/vm/drop_caches Clear cache LSI controller: megacli -AdpCacheFlush -a0 dd if=/mnt/from/random of=/mnt/sda8/random bs=512k oflag=direct,dsync iostat show me the statistic: iostat -cdm 1 /dev/sda /dev/sdr Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 3021.00 0.01 318.00 0 318 sdr 2410.00 301.25 0.00 301 0 I think my cluster have a bottle neck in journal block size. How I can increase the size of block for journal? -- Best regards, Mike.