It seems that for some reason, when commissioning a Xenial node, the StatusHandler runs multiple times. For example, from my maas.log:
Feb 11 21:50:59 maastest maas.node: [INFO] triple-managed1: Storage layout was set to flat.
Feb 11 21:51:02 maastest maas.node: [INFO] triple-managed1: Storage layout was set to flat.
Feb 11 21:52:16 maastest maas.node: [INFO] triple-managed1: Storage layout was set to flat.
It seems that for some reason, when commissioning a Xenial node, the StatusHandler runs multiple times. For example, from my maas.log:
Feb 11 21:50:59 maastest maas.node: [INFO] triple-managed1: Storage layout was set to flat.
Feb 11 21:51:02 maastest maas.node: [INFO] triple-managed1: Storage layout was set to flat.
Feb 11 21:52:16 maastest maas.node: [INFO] triple-managed1: Storage layout was set to flat.
This was from a single commissioning attempt.
I believe that is the root cause of this issue.