From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43966) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fk9oN-0003Dt-2H for qemu-devel@nongnu.org; Mon, 30 Jul 2018 11:10:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fk9oM-0008Hr-6F for qemu-devel@nongnu.org; Mon, 30 Jul 2018 11:10:15 -0400 From: Kevin Wolf Date: Mon, 30 Jul 2018 17:09:49 +0200 Message-Id: <20180730150958.14607-5-kwolf@redhat.com> In-Reply-To: <20180730150958.14607-1-kwolf@redhat.com> References: <20180730150958.14607-1-kwolf@redhat.com> Subject: [Qemu-devel] [PULL 04/13] docs: Describe using images in writing iotests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-block@nongnu.org Cc: kwolf@redhat.com, peter.maydell@linaro.org, qemu-devel@nongnu.org From: Fam Zheng Signed-off-by: Fam Zheng Reviewed-by: Eric Blake Reviewed-by: John Snow Signed-off-by: Kevin Wolf --- docs/devel/testing.rst | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst index 5e19cd50da..8e1fa3a66e 100644 --- a/docs/devel/testing.rst +++ b/docs/devel/testing.rst @@ -255,6 +255,17 @@ comparable library support for invoking and interacting with QEMU programs. If you opt for Python, it is strongly recommended to write Python 3 compatible code. +Both Python and Bash frameworks in iotests provide helpers to manage test +images. They can be used to create and clean up images under the test +directory. If no I/O or any protocol specific feature is needed, it is often +more convenient to use the pseudo block driver, ``null-co://``, as the test +image, which doesn't require image creation or cleaning up. Avoid system-wide +devices or files whenever possible, such as ``/dev/null`` or ``/dev/zero``. +Otherwise, image locking implications have to be considered. For example, +another application on the host may have locked the file, possibly leading to a +test failure. If using such devices are explicitly desired, consider adding +``locking=off`` option to disable image locking. + Docker based tests ================== -- 2.13.6