At 8:00 AM PDT (15:00 UTC), Monday May 4th the long-term vault/vos storage system (https://ws-cadc.canfar.net/vault) will be placed in read-only mode to enable a database hardware upgrade. The DOI (https://ws-cadc.canfar.net/doi) and RAFTS services (https://ws-cadc.canfar.net/rdoi) will also be read-only during this upgrade. The upgrade is expected to take several hours. The upgrade status can be monitored here: https://cadc.statuspage.io/