[PATCH docs] qdevice: correct qdevice partition tie breaking section.

Manuel Federanko
2026-02-20T12:56:57Z

The partition that gets a vote is not randomly chosen, but depends on
the configuration of the qdevice in corosync.conf.

A partner asked about predictable behavior for vote casting by the
QDevice. The documentation of corosync and ours didn't align.

Setting tie_breaker influences how a partition is chosen for votes,
which was tested with a 2-node test-cluster.

Signed-off-by: Manuel Federanko <m.federanko@proxmox.com>
---
pvecm.adoc | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/pvecm.adoc b/pvecm.adoc
index 0ed1bd2..899a4de 100644
--- a/pvecm.adoc
+++ b/pvecm.adoc
@@ -1266,8 +1266,10 @@ Tie Breaking
^^^^^^^^^^^^

In case of a tie, where two same-sized cluster partitions cannot see each other
-but can see the QDevice, the QDevice chooses one of those partitions randomly
-and provides a vote to it.
+but can see the QDevice, the QDevice chooses the partition which has
+the lowest node id and provides a vote to it. This behavior can be tuned with
+the configuration option `tie_breaker` (see `man corosync-qdevice` for more
+information) and requires a restart of `corosync-qdevice.service` on all nodes.

Possible Negative Implications
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
--
2.47.3