MySQL Enterprise Backup User's Guide (Version 4.1.5)
        Inside the image backup file created by the
        backup-to-image command of
        mysqlbackup are some new files that are
        produced during the backup process. These files are used to
        control later tasks such as verifying and restoring the backup
        data. The files generated during the backup process include:
        
              meta/backup_create.xml: Lists the
              command line arguments and environment in which the backup
              was created.
            
              meta/backup_content.xml: Essential
              metadata for the files and database definitions of the
              backup data.
            
              backup-my.cnf: Records the crucial
              configuration parameters that apply to the backup. These
              configuration parameters are read by
              mysqlbackup during operations like
              apply-log to determine how the
              backup data is structured. These parameters are also
              checked during a restore operation for their compatibility
              with your target server's configuration.
            
              server-my.cnf: Contains values of the
              backed-up server's global variables that are set to
              non-default values.
            
              server-all.cnf: Contains values of
              all the global variables of the backed-up server.
            
              *.bkt: Transfer file created for an
              encrypted InnoDB table during backup. It contains the
              reencrypted tablespace key and other information related
              to the encryption. See
              Chapter 6, Working with Encrypted InnoDB Tables for detail.
            
For details about these are other files contained in the backup, see Table 1.1, “Types of Files in a Backup”.