From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38448) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dVxLf-0003qV-7j for qemu-devel@nongnu.org; Fri, 14 Jul 2017 05:57:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dVxLe-0008CS-B3 for qemu-devel@nongnu.org; Fri, 14 Jul 2017 05:57:23 -0400 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:49283 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 1dVxLe-0008Ar-1k for qemu-devel@nongnu.org; Fri, 14 Jul 2017 05:57:22 -0400 From: Peter Lieven Date: Fri, 14 Jul 2017 11:56:40 +0200 Message-Id: <1500026205-15542-5-git-send-email-pl@kamp.de> In-Reply-To: <1500026205-15542-1-git-send-email-pl@kamp.de> References: <1500026205-15542-1-git-send-email-pl@kamp.de> Subject: [Qemu-devel] [PATCH V3 4/9] qemu-img: add documentation for compress settings List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, kwolf@redhat.com, lersek@redhat.com, den@openvz.org, mreitz@redhat.com, eblake@redhat.com, berrange@redhat.com, Peter Lieven Signed-off-by: Peter Lieven --- qemu-img.texi | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/qemu-img.texi b/qemu-img.texi index f11f603..79b0182 100644 --- a/qemu-img.texi +++ b/qemu-img.texi @@ -669,6 +669,26 @@ 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: + + zlib Uses standard zlib compression + +The compression algorithm can only be defined at image create time and cannot +be changed later. + +Note: defining a compression format will result in the compression format + extension being written to the Qcow2 image. Versions of QEMU before 2.10 + will not be able to open images with this extension. + +@item compress.level +Valid for compress.format=zlib 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. + @end table @item Other -- 1.9.1