# Index of files created by Percona XtraBackup


* Information related to the backup and the server

| File Name                           | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| ----------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| `backup-my.cnf`                     | This file contains information to start the mini-instance of InnoDB during the `--prepare`. This **not** a backup of the original `my.cnf`. The InnoDB configuration is read from the file `backup-my.cnf` created by **xtrabackup** when the backup was made. The `--prepare` uses InnoDB configuration from `backup-my.cnf` by default, or from `--defaults-file`, if specified. The InnoDB's configuration in this context means server variables that affect dataformat, i.e. `innodb_page_size` option, `innodb_log_block_size`, etc. Location-related variables, like `innodb_log_group_home_dir` or `innodb_data_file_path` are always ignored by `--prepare`, so preparing a backup always works with data files from the back directory, rather than any external ones. |
| `xtrabackup_checkpoints`            | The type of the backup (for example, full or incremental), its state (for example, prepared) and the LSN range contained in it. This information is used for incremental backups. Example of the `xtrabackup_checkpoints` after taking a full backup: `backup_type = full-backuped from lsn= 0 to_lsn = 15188961605 last_lsn = 15188961605` Example of the `xtrabackup_checkpoints` after taking an incremental backup: `backup_type = incremental from_lsn = 15188961605 to_lsn = 15189350111 last_lsn = 15189350111`                                                                                                                                                                                                                                                      |
| `xtrabackup_binlog_info`            | The binary log file used by the server and its position at the moment of the backup. A result of the following query: `SELECT server_uuid, local, replication, storage_engines FROM performance_schema.log_status;`                                                                                                                                                                                                                                                                                                                                                                             |
| `xtrabackup_binlog`                 | The **xtrabackup** binary used in the process.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
| `xtrabackup_logfile`                | Contains data needed for running the: `--prepare`. The bigger this file is the `--prepare` process will take longer to finish.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| `<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: `page_size = 16384 zip_size = 0 space_id = 0`                                                                                                                                                                                                                                                                                                                                                      |

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

    `xtrabackup_slave_info`

    The `CHANGE MASTER` statement needed for setting up a replica.

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

    `xtrabackup_galera_info`
   
    Contains the values of `wsrep_local_state_uuid` and`wsrep_last_committed` status variables