If the mysqlbackup command encounters problems during operating system calls, it returns the corresponding OS error codes. You might need to consult your operating system documentation for the meaning and solution of these error codes.

Incremental backups require care to specify a sequence of time periods You must record the final LSN value at the end of each backup, and specify that value in the next incremental backup. You must also make sure that the full backup you restore is prepared correctly first, so that it contains all the changes from the sequence of incremental backups.

As the mysqlbackup command proceeds, it writes progress information into the mysql.backup_progress table. When the command finishes the backup operation, it records status information in the mysql.backup_history table. You can query these tables to monitor ongoing jobs, see how much time was needed for various stages, and check if any errors occurred.