From: Kevin Wolf <kwolf@redhat.com>
Date: Thu, 16 Aug 2012 08:56:35 +0000 (+0200)
Subject: Documentation: Warn against qemu-img on active image
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=48467328c6dccc9c7be6628ed0ef0810f83be2a9;p=qemu.git

Documentation: Warn against qemu-img on active image

People have repeatedly expected that you can do things like snapshotting
an image with qemu-img while a qemu instance is running. Maybe we need
to consider locking the files while they are in use, but having a
warning in the qemu-img manpage is doable for 1.2 and can't hurt anyway.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---

diff --git a/qemu-img.texi b/qemu-img.texi
index 77c6d0b6b0..6b42e35fe7 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -4,6 +4,16 @@ usage: qemu-img command [command options]
 @c man end
 @end example
 
+@c man begin DESCRIPTION
+qemu-img allows you to create, convert and modify images offline. It can handle
+all image formats supported by QEMU.
+
+@b{Warning:} Never use qemu-img to modify images in use by a running virtual
+machine or any other process; this may destroy the image. Also, be aware that
+querying an image that is being modified by another process may encounter
+inconsistent state.
+@c man end
+
 @c man begin OPTIONS
 
 The following commands are supported: