We have completed all of the updates and reboots for the hypervisors and instances in https://phabricator.wikimedia.org/T184910, but there are more maintenance events that are less invasive to come. This is being tracked in https://phabricator.wikimedia.org/T184910
Most of this will be handled gracefully without user impact, but not all of it.
We will reboot the `dumps` NFS server that also provides the `maps` and `scratch` NFS shares tomorrow (1/18/2018). Note the reason this is an outage event is that this server is a single point of failure. Efforts to improve this are happening in https://phabricator.wikimedia.org/T168486
More announcements will come for maintenance that is impactful.