.. _xtrabackup_files :

============================================
Index of files created by Percona XtraBackup
============================================

* Information related to the backup and the server

    * :file:`backup-my.cnf`
       This file contains information to start the mini instance of InnoDB during the :option:`--apply-log`. This is **NOT** a backup of original :file:`my.cnf`.  The InnoDB configuration is read from the file :file:`backup-my.cnf` created by |innobackupex| when the backup was made. :option:`innobackupex --apply-log` uses InnoDB configuration from ``backup-my.cnf`` by default, or from :option:`innobackupex --defaults-file`, if specified. InnoDB configuration in this context means server variables that affect data format, i.e. :option:`innodb_page_size`, :option:`innodb_log_block_size`, etc. Location-related variables, like :option:`innodb_log_group_home_dir` or :option:`innodb_data_file_path` are always ignored by :option:`innobackupex --apply-log`, so preparing a backup always works with data files from the backup directory, rather than any external ones.


    * :file:`xtrabackup_checkpoints`
       The type of the backup (e.g. full or incremental), its state (e.g. prepared) and the |LSN| range contained in it. This information is used for incremental backups.
       Example of the :file:`xtrabackup_checkpoints` after taking a full backup: :: 
        
        backup_type = full-backuped
        from_lsn = 0
        to_lsn = 15188961605
        last_lsn = 15188961605

       Example of the :file:`xtrabackup_checkpoints` after taking an incremental backup: :: 
      
        backup_type = incremental
        from_lsn = 15188961605
        to_lsn = 15189350111
        last_lsn = 15189350111

    * :file:`xtrabackup_binlog_info`
       The binary log file used by the server and its position at the moment of the backup. Result of the :command:`SHOW MASTER STATUS`.

    * :file:`xtrabackup_binlog_pos_innodb`
       The binary log file and its current position for |InnoDB| or |XtraDB| tables.

    * :file:`xtrabackup_binary`
       The |xtrabackup| binary used in the process.
    
    * :file:`xtrabackup_logfile` 
       Contains data needed for running the: :option:`--apply-log`. The bigger this file is the :option:`--apply-log` process will take longer to finish. 

    * :file:`<table_name>.delta.meta`
       This file is going to be created when performing the incremental backup. It contains the per-table delta metadata: page size, size of compressed page (if the value is 0 it means the tablespace isn't compressed) and space id. Example of this file could looks like this: :: 

        page_size = 16384
        zip_size = 0
        space_id = 0

    * :file:`<table_name>.ibd.pmap`
       This file contains ranges of skipped secondary index pages. These files are created only when doing the compact backup. The file format is a series of 2-value tuples, with each value being a 4-byte page offset corresponding to the first and the last endpoints of skipped ranges, respectively.

* Information related to the replication environment (if using the :option:`--slave-info` option):

    * :file:`xtrabackup_slave_info`
       The ``CHANGE MASTER`` statement needed for setting up a slave.

* Information related to the *Galera* and *Percona XtraDB Cluster* (if using the :option:`--galera-info` option):

    * :file:`xtrabackup_galera_info`
       Contains the values of status variables :option:`wsrep_local_state_uuid` and :option:`wsrep_last_committed`.
