Access to all TACC systems will be unavailable from 7:00 AM CDT on July 18 until 8:00 AM CDT on July 19 to allow for upgrades to the core network switch hardware and to perform system maintenance on the Stockyard global filesystem. Users will have intermittent access to all TACC services and systems until the core network switch upgrade is complete. During this maintenance window, the production systems Stampede2, Stampede, Lonestar5, Maverick, Wrangler and Hikari will also be down for system maintenance and unavailable to users until after the Stockyard global file system maintenance has been completed. Updates to user news will be sent once network services have been restored and when the production systems are restored to normal operations.