Re: [PATCH] qemu: Don't compare local and remote hostnames on migration
On Mon, Mar 02, 2020 at 09:17:27AM +0100, Michal Privoznik wrote:
Libvirt tries to forbid migration onto the same host and it does
that by checking if local and remote hostnames are the same and
whether local and remote UUIDs are the same. Well, the latter
makes sense but the former doesn't really because libvirtd can be
running inside an UTS namespace and hostnames can appear the same
on both sides of migration. On the other hand, host UUIDs are
unique, so rely on them when trying to prevent migration onto the
same host.
This check originates in
commit 8654175c5b0c3db9e5f70907f102f0f900355d28
Author: Daniel P. Berrangé <berrange(a)redhat.com>
Date: Mon Jan 24 18:06:16 2011 +0000
Introduce migration cookies to QEMU driver
We've always had both hostname and uuid checks here, as a way to
prevent localhost-migration. The only way I can think to bypass
the UUID check is to run a second libvirtd on the same host,
but inside a container so you can change UUID or libvirtd.conf.
At that point, you can set things up so that you are safe todo a
local migration, so its ok to allow for that.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1639596
Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com>
---
src/qemu/qemu_migration_cookie.c | 12 +++++-------
1 file changed, 5 insertions(+), 7 deletions(-)
Reviewed-by: Daniel P. Berrangé <berrange(a)redhat.com>
Regards,
Daniel
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