Patchwork [3/4] Documentation: Warn against qemu-img on active image

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Submitter Kevin Wolf
Date Aug. 17, 2012, 7:25 p.m.
Message ID <>
Download mbox | patch
Permalink /patch/178339/
State New
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Kevin Wolf - Aug. 17, 2012, 7:25 p.m.
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 <>
 qemu-img.texi |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)


diff --git a/qemu-img.texi b/qemu-img.texi
index 77c6d0b..77b2c47 100644
--- a/qemu-img.texi
+++ b/qemu-img.texi
@@ -4,6 +4,14 @@  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.
+@c man end
 @c man begin OPTIONS
 The following commands are supported: