From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from p3nlsmtpcp01-01.prod.phx3.secureserver.net ([184.168.200.138]:43884 "EHLO p3nlsmtpcp01-01.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752662AbdBRCIZ (ORCPT ); Fri, 17 Feb 2017 21:08:25 -0500 Received: from [59.93.14.58] (port=59614 helo=giis.co.in) by p3plcpnl0639.prod.phx3.secureserver.net with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.87) (envelope-from ) id 1ceuQl-000569-BW for linux-btrfs@vger.kernel.org; Fri, 17 Feb 2017 19:07:24 -0700 Date: Sat, 18 Feb 2017 07:37:11 +0530 From: "Lakshmipathi.G" To: linux-btrfs@vger.kernel.org Subject: Large no.of extents for a single small file with a fresh RAID5 setup Message-ID: <20170218020711.GA23608@giis.co.in> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi, With RAID5, using 3 loop-back devices each has 4GB. On a fresh setup, created a 2mb file. While checking no.of extents,it shows like: # ./btrfs-debugfs -f /mnt/file2m.txt (257 0): ram 110592 disk 145227776 disk_size 114688 (257 110592): ram 4096 disk 145461248 disk_size 4096 (257 114688): ram 114688 disk 145342464 disk_size 118784 (257 229376): ram 712704 disk 145620992 disk_size 716800 (257 942080): ram 4096 disk 145096704 disk_size 4096 (257 946176): ram 737280 disk 146407424 disk_size 741376 (257 1683456): ram 413696 disk 147193856 disk_size 413696 file: /mnt/file2m.txt extents 7 disk size 2113536 logical size 2097152 ratio 0.99 Is this expected behaviour? Is there any mount option to minimize no.of extents for a smaller file? Cheers. Lakshmipathi.G