CREATE LOGFILE GROUP Statement [NODEGROUP [=]  nodegroup_id ] [WAIT] [COMMENT [=] ’ string ’] ENGINE [=]  engine_name This statement creates a new log file group named  logfile_group  having a single  UNDO  file named ’ undo_file ’. A  CREATE LOGFILE GROUP  statement has one and only one  ADD UNDOFILE  clause. For rules covering the naming of log file groups, see Section 9.2, “Schema Object Names” . Note All NDB Cluster Disk Data objects share the same namespace. This means that each Disk Data object  must be uniquely named (and not merely each Disk Data object of a given type). For example, you cannot have a tablespace and a log file group with the same name, or a tablespace and a data file with the same name. There can be only one log file group per NDB Cluster instance at any given time. The optional  INITIAL_SIZE  parameter sets the  UNDO  file’s initial size; if not specified, it defaults to  128M (128 megabytes). The optional  UNDO_BUFFER_SIZE  parameter sets the size used by the  UNDO  buffer for the log file group; The default value for  UNDO_BUFFER_SIZE  is  8M  (eight megabytes); this value cannot exceed the amount of system memory available. Both of these parameters are specified in bytes. You may optionally follow either or both of these with a one-letter abbreviation for an order of magnitude, similar to those used in  my.cnf . Generally, this is one of the letters  M  (for megabytes) or  G  (for gigabytes). Memory used for  UNDO_BUFFER_SIZE  comes from the global pool whose size is determined by the value of the  SharedGlobalMemory  data node configuration parameter. This includes any default value implied for this option by the setting of the  InitialLogFileGroup  data node configuration parameter. The maximum permitted for  UNDO_BUFFER_SIZE  is 629145600 (600 MB). On 32-bit systems, the maximum supported value for  INITIAL_SIZE  is 4294967296 (4 GB). (Bug #29186) The minimum allowed value for  INITIAL_SIZE  is 1048576 (1 MB). The  ENGINE  option determines the storage engine to be used by this log file group, with  engine_name being the name of the storage engine. In MySQL 8.0, this must be  NDB  (or  NDBCLUSTER ). If  ENGINE  is not set, MySQL tries to use the engine specified by the  default_storage_engine  server system variable (formerly  storage_engine ). In any case, if the engine is not specified as  NDB  or  NDBCLUSTER , the CREATE LOGFILE GROUP  statement appears to succeed but actually fails to create the log file group, as shown here: mysql>  CREATE LOGFILE GROUP lg1 -> ADD UNDOFILE ’undo.dat’ INITIAL_SIZE = 10M; Query OK, 0 rows affected, 1 warning (0.00 sec) mysql>  SHOW WARNINGS; mysql>  DROP LOGFILE GROUP lg1 ENGINE = NDB; ERROR 1529 (HY000): Failed to drop LOGFILE GROUP mysql>  CREATE LOGFILE GROUP lg1 -> ADD UNDOFILE ’undo.dat’ INITIAL_SIZE = 10M | Level | Code | Message | Error | 1478 | Table 1 row in set (0.00 sec) 2529