The Clone Plugin mysql> SHOW VARIABLES LIKE ’max_allowed_packet’; The following prerequisites also apply: To view undo tablespace file names on the donor to ensure that they are unique, query INFORMATION_SCHEMA.FILES : mysql> SELECT TABLESPACE_NAME, FILE_NAME FROM INFORMATION_SCHEMA.FILES WHERE FILE_TYPE LIKE ’UNDO LOG’; For information about dropping and adding undo tablespace files, see Section 15.6.3.4, “Undo Tablespaces” . ERROR 3707 (HY000): Restart server failed (mysqld is not managed by supervisor process). This error does not indicate a cloning failure. It means that the recipient MySQL server instance must be started again manually after the data is cloned. After starting the server manually, you can connect to the recipient MySQL server instance and check the Performance Schema clone tables to verify that the cloning operation completed successfully (see Monitoring Cloning Operations using Performance Schema Clone Tables.) The  RESTART  statement has the same monitoring process requirement. For more information, see Section 13.7.8.8, “RESTART Statement” . This requirement is not applicable if cloning to a named directory using the  DATA DIRECTORY  clause, as an automatic restart is not performed in this case. The following example demonstrates cloning remote data. By default, a remote cloning operation removes the data in the recipient data directory, replaces it with the cloned data, and restarts the MySQL server afterward. The example assumes that remote cloning prerequisites are met. See Remote Cloning Prerequisites. 1116 •There must be no other cloning operation running. Only a single cloning operation is permitted at a time. To determine if a clone operation is running, query the  clone_status  table. See Monitoring Cloning Operations using Performance Schema Clone Tables. •The clone plugin transfers data in 1MB packets plus metadata. The minimum required max_allowed_packet  value is therefore 2MB on the donor and the recipient MySQL server instances. A  max_allowed_packet  value less than 2MB results in an error. Use the following query to check your max_allowed_packet  setting: •Undo tablespace file names on the donor must be unique. When data is cloned to the recipient, undo tablespaces, regardless of their location on the donor, are cloned to the  innodb_undo_directory location on the recipient or to the directory specified by the  DATA DIRECTORY [=] ’ clone_dir ’ clause, if used. Duplicate undo tablespace file names on the donor are not permitted for this reason. As of MySQL 8.0.18, an error is reported if duplicate undo tablespace file names are encountered during a cloning operation. Prior to MySQL 8.0.18, cloning undo tablespaces with the same file name could result in undo tablespace files being overwritten on the recipient. •By default, the recipient MySQL server instance is restarted (stopped and started) automatically after the data is cloned. For an automatic restart to occur, a monitoring process must be available on the recipient to detect server shutdowns. Otherwise, the cloning operation halts with the following error after the data is cloned, and the recipient MySQL server instance is shut down: •Several variables control various aspects of a remote cloning operation. Before performing a remote cloning operation, review the variables and adjust settings as necessary to suit your computing environment. Clone variables are set on recipient MySQL server instance where the cloning operation is executed. See Section 5.6.7.12, “Clone System Variables” . Cloning Remote Data