Server Command Options FORCE This option controls whether and how the server performs an automatic upgrade at startup. Automatic upgrade involves two steps: This step upgrades: This step comprises all other upgrade tasks. If the existing installation data has a lower MySQL version than the server expects, it must be upgraded: For details about upgrade steps 1 and 2, see Section 2.11.3, “What the MySQL Upgrade Process Upgrades” . These  --upgrade  option values are permitted: The server performs an automatic upgrade of anything it finds to be out of date (steps 1 and 2). This is the default action if  --upgrade  is not specified explicitly. The server performs no automatic upgrade steps during the startup process (skips steps 1 and 2). Because this option value prevents a data dictionary upgrade, the server exits with an error if the data dictionary is found to be out of date: The server upgrades the data dictionary, the Performance Schema, and the  INFORMATION_SCHEMA , if necessary (step 1). Note that following an upgrade with this option, Group Replication cannot 759 [ERROR] [MY-013381] [Server] Server shutting down because upgrade is required, yet prohibited by the command line option ’--upgrade=NONE’. [ERROR] [MY-010334] [Server] Failed to initialize DD Storage Engine [ERROR] [MY-010020] [Server] Data Dictionary initialization failed. • MINIMAL • NONE • AUTO •User schemas. •The  sys  schema. •The system tables in the  mysql  schema (the remaining non-data dictionary tables). •Step 2: Server upgrade. •The Performance Schema and  INFORMATION_SCHEMA . •The data dictionary tables in the  mysql  schema. If the actual data dictionary version is lower than the current expected version, the server upgrades the data dictionary. If it cannot, or is prevented from doing so, the server cannot run. •Step 1: Data dictionary upgrade.