deployment-mediawiki02 labs instance only has 2GB of disk which highlight an hhvm issue. The hhvm upstart process emits log to /var/log/upstart/hhvm.log which contains a bunch of php notices. That is also send to syslog ( /var/log/syslog/ ) creating a snowball effect that completely fill up /var/.
The hhvm upstart job should be made to discard anything that is below the 'error' level and the notices be sent to a central syslog.
Version: unspecified
Severity: major