The Lewis cluster will undergo urgent maintenance Wednesday 6/28. There is a set of urgent security patches that need to be applied to the cluster that will require a reboot. These relate to a series of vulnerabilities that have been receiving a lot of attention, you can find more information at https://access.redhat.com/security/vulnerabilities/stackguard. We will start patching on Wednesday 6/28 at 8:00 am unless an exploit goes public before then at which point there may be an emergency patch depending on the situation. We hope patching will be complete by the end of the day on Wednesday. Linux users should also ensure that their systems are up to date as well.
Jobs will continue to run as long as they are scheduled to complete by 8:00 am on Wednesday. We also plan on preserving the queue, so pending jobs will start after patching is complete.
— Jun. 22, 2017