From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fyodor Ustinov Subject: increase duplication level decrease performance Date: Mon, 4 Apr 2011 21:55:04 +0000 (UTC) Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from lo.gmane.org ([80.91.229.12]:40775 "EHLO lo.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753148Ab1DDWPK (ORCPT ); Mon, 4 Apr 2011 18:15:10 -0400 Received: from list by lo.gmane.org with local (Exim 4.69) (envelope-from ) id 1Q6s3A-0007ae-EV for ceph-devel@vger.kernel.org; Tue, 05 Apr 2011 00:15:08 +0200 Received: from 94.232.181.14 ([94.232.181.14]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 05 Apr 2011 00:15:08 +0200 Received: from ufm by 94.232.181.14 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 05 Apr 2011 00:15:08 +0200 Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org Hi. ceph osd pool set data size 1 dd if=/dev/zero of=aaa bs=1024000 count=4000 4096000000 bytes (4.1 GB) copied, 31.3153 s, 131 MB/s ceph osd pool set data size 2 4096000000 bytes (4.1 GB) copied, 72.7146 s, 56.3 MB/s ceph osd pool set data size 3 4096000000 bytes (4.1 GB) copied, 136.263 s, 30.1 MB/s Why? I thought increase in the number of copies should increase the performance (in the worst case does not affect). WBR, Fyodor.