[Libguestfs] [PATCH 3/5] tools: Make warnings about running on live guests more prominent.
Richard W.M. Jones
rjones at redhat.com
Mon Oct 19 11:24:34 UTC 2009
A timely warning not to try running certain tools on live VMs.
Sys::Guestfs::Lib detects this some of the time, but can't do
it always.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines. Boot with a
live CD or over the network (PXE) and turn machines into Xen guests.
http://et.redhat.com/~rjones/virt-p2v
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>From 5c4bf92bc298e078ceccdde603313282d038544c Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones at redhat.com>
Date: Mon, 19 Oct 2009 10:45:44 +0100
Subject: [PATCH 3/5] tools: Make warnings about running on live guests more prominent.
Add prominent warnings to the man pages about how it is dangerous
to run these tools against live guests.
---
tools/virt-edit | 9 ++++++---
tools/virt-rescue | 16 ++++++++++------
2 files changed, 16 insertions(+), 9 deletions(-)
diff --git a/tools/virt-edit b/tools/virt-edit
index 46e86a1..9196a66 100755
--- a/tools/virt-edit
+++ b/tools/virt-edit
@@ -40,14 +40,17 @@ virt-edit - Edit a file in a virtual machine
virt-edit [--options] disk.img [disk.img ...] file
+=head1 WARNING
+
+You must I<not> use C<virt-edit> on live virtual machines. If you do
+this, you risk disk corruption in the VM. C<virt-edit> tries to stop
+you from doing this, but doesn't catch all cases.
+
=head1 DESCRIPTION
C<virt-edit> is a command line tool to edit C<file> where C<file>
exists in the named virtual machine (or disk image).
-B<Note> you must I<not> use virt-edit on live virtual machines. If
-you do this, you risk disk corruption in the VM.
-
If you want to just view a file, use L<virt-cat(1)>. For more complex
cases you should look at the L<guestfish(1)> tool.
diff --git a/tools/virt-rescue b/tools/virt-rescue
index 9ad2fa4..4f90ab1 100755
--- a/tools/virt-rescue
+++ b/tools/virt-rescue
@@ -37,6 +37,16 @@ virt-rescue - Run a rescue shell on a virtual machine
virt-rescue [--options] disk.img [disk.img ...]
+=head1 WARNING
+
+You must I<not> use C<virt-rescue> on live virtual machines. Doing so
+will probably result in disk corruption in the VM. C<virt-rescue>
+tries to stop you from doing this, but doesn't catch all cases.
+
+However if you use the I<--ro> (read only) option, then you can attach
+a shell to a live virtual machine, but the results might be strange or
+inconsistent at times (but you won't get disk corruption).
+
=head1 DESCRIPTION
virt-rescue gives you a rescue shell and some simple recovery tools
@@ -53,12 +63,6 @@ eg:
# mount /dev/vg_f11x64/lv_root /sysroot
# ls /sysroot
-B<Note> that the virtual machine must not be powered on when you use
-this tool. Doing so will probably result in disk corruption in the
-VM. However if you use the I<--ro> (read only) option, then you can
-attach a shell to a running machine, but the results might be strange
-or inconsistent.
-
This tool is just designed for quick interactive hacking on a virtual
machine. For more structured access to a virtual machine disk image,
you should use L<guestfs(3)>. To get a structured shell, use
--
1.6.5.rc2
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