From patchwork Tue Jul 25 14:41:33 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Lieven X-Patchwork-Id: 793464 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=2001:4830:134:3::11; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3xH1Tq0Gc8z9s72 for ; Wed, 26 Jul 2017 00:54:07 +1000 (AEST) Received: from localhost ([::1]:33001 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1da1Do-0002sP-Ur for incoming@patchwork.ozlabs.org; Tue, 25 Jul 2017 10:54:05 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:36626) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1da12F-000221-2n for qemu-devel@nongnu.org; Tue, 25 Jul 2017 10:42:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1da12D-00011x-5s for qemu-devel@nongnu.org; Tue, 25 Jul 2017 10:42:07 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:52305 helo=mx01.kamp.de) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1da12C-00010s-Sz for qemu-devel@nongnu.org; Tue, 25 Jul 2017 10:42:05 -0400 Received: (qmail 15793 invoked by uid 89); 25 Jul 2017 14:42:03 -0000 Received: from [195.62.97.28] by client-16-kamp (envelope-from , uid 89) with qmail-scanner-2010/03/19-MF (clamdscan: 0.99.2/23595. avast: 1.2.2/17010300. spamassassin: 3.4.1. 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Processed in 0.272009 secs); 25 Jul 2017 14:42:03 -0000 Received: from smtp.kamp.de (HELO submission.kamp.de) ([195.62.97.28]) by mx01.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted); 25 Jul 2017 14:42:00 -0000 X-GL_Whitelist: yes Received: (qmail 9633 invoked from network); 25 Jul 2017 14:41:40 -0000 Received: from lieven-pc.kamp-intra.net (HELO lieven-pc) (relay@kamp.de@::ffff:172.21.12.60) by submission.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted) ESMTPA; 25 Jul 2017 14:41:40 -0000 Received: by lieven-pc (Postfix, from userid 1000) id 53D2920ECB; Tue, 25 Jul 2017 16:41:40 +0200 (CEST) From: Peter Lieven To: qemu-block@nongnu.org Date: Tue, 25 Jul 2017 16:41:33 +0200 Message-Id: <1500993699-19299-5-git-send-email-pl@kamp.de> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1500993699-19299-1-git-send-email-pl@kamp.de> References: <1500993699-19299-1-git-send-email-pl@kamp.de> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a02:248:0:51::16 Subject: [Qemu-devel] [PATCH V5 04/10] qemu-img: add documentation for compress settings X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, Peter Lieven , qemu-devel@nongnu.org, mreitz@redhat.com, den@openvz.org, lersek@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Signed-off-by: Peter Lieven --- qemu-img.texi | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/qemu-img.texi b/qemu-img.texi index 72dabd6..3612c59 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -676,6 +676,32 @@ file which is COW and has data blocks already, it couldn't be changed to NOCOW by setting @code{nocow=on}. One can issue @code{lsattr filename} to check if the NOCOW flag is set or not (Capital 'C' is NOCOW flag). +@item compress.format +Defines which compression algorithm is should be used for compressed clusters. +The following options are available if support for the respective libraries +has been enabled at compile time: + + deflate Uses standard zlib defalte compression + +The compression algorithm can only be defined at image create time and cannot +be changed later. + +Note: defining compression format settings which are different from the old + default (format=deflate, level=0, window-size=12) will result in the + compression format extension being written to the Qcow2 image. Versions + of QEMU before 2.11 will not be able to open images with this extension. + +@item compress.level +Valid for compress.format=deflate defines the compression level to use for +selected compression format. The default of @code{compress.level=0} will use +the default compression level for the format. Alternate values range from 1 for +fastest compression to 9 for the best compression. + +@item compress.window-size +Valid for compress.format=deflate defines the compression window size used +during compression. Valid window sizes for deflate compression range from 8 to +15 inclusively. The default is @code{compress.window-size=15}. + @end table @item Other