Comment 20 for bug 1623853

excerpt of syslog corresponding to first boot after upgrade.

From syslog there is a 2 minutes gap in the syslog timestamp compared to the kernel timestamp
Sep 21 07:38:19 ubuntu-phablet kernel: [ 74.454170]PM: suspend exit 2016-09-21 05:38:19.199271077 UTC
Sep 21 07:38:19 ubuntu-phablet kernel: [ 74.454218]PM: suspend entry 2016-09-21 05:38:19.199318385 UTC
Sep 21 07:40:05 ubuntu-phablet kernel: [ 74.454229]PM: Syncing filesystems ... done.
Sep 21 07:40:05 ubuntu-phablet kernel: [ 74.465804][pm_notifier_call_chain]: there are 4 notify callbacks, event = 3

From unity8.log.1.gz
[2016-09-21 07:40:52.105060] mirserver: Starting