20.7 Incremental Backup Options

For an overview of incremental backups and usage examples for these options, see Section 4.3.3, “Making a Differential or Incremental Backup” and Section 5.1.3, “Restoring an Incremental Backup”.

To take an incremental backup, specify the --incremental or --incremental-with-redo-log-only, along with the --backup-dir option. Depending on whether --incremental or --incremental-with-redo-log-only is used, other options are required or recommended. All InnoDB data modified after the LSN (specified directly or indirectly by the options you use) is copied into the incremental backup.

• --incremental[={page-track|full-scan|optimistic}]

  Command-Line Format	--incremental
  Type	Enumeration
  Default Value	page-track
  Valid Values	page-track full-scan optimistic

  Possible values for this option and their effects are explained further in the following list:

  • page-track: mysqlbackup looks for changed pages in InnoDB data files that have been modified since the last backup, using the page tracking functionality on the server, and then copies them. This is potentially the fastest way for mysqlbackup to create incremental backups.

    If page tracking cannot be used (see Incremental Backup Using Page Tracking) and --incremental is not set explicitly, mysqlbackup performs a full-scan backup instead. If this value has been set explicitly but page tracking cannot be used, the backup fails with an error.

  • full-scan: mysqlbackup scans all InnoDB data files in the server data directory to find pages that have been changed since the last backup, and copies them.

  • optimistic: mysqlbackup scans only for changed pages in the InnoDB data files that have been modified since the last backup and then copies them. In general, optimistic incremental backups are faster than full-scan backups when not many tables in the database have been modified. Some restrictions apply when this option is employed; see Full-scan versus Optimistic Incremental Backup.

  --incremental also requires the use of either --incremental-base or --start-lsn. Only InnoDB tables are backed up incrementally. By default, all files are included in the incremental backup in their entirety. To exclude data that is not specific to InnoDB in an incremental backup, use --only-innodb.

  When --copy-back-and-apply-log, --copy-back, or --apply-log is used, there is no need to use --incremental.

• --incremental-with-redo-log-only

  Specifies that an incremental backup is to be created using only the redo log. This alternate type of incremental backup has different performance characteristics and operational limitations compared to backups created with the --incremental option; see Creating Incremental Backups Using Only the Redo Log for a discussion on their differences, and for how to perform properly a redo-log-only incremental backup.

  To use this option, you also need to specify the --incremental-base option or the --start-lsn. Just like with the --incremental option, only InnoDB tables are backed up incrementally. By default, all non-InnoDB files are included into the incremental backup and in their fullness. To exclude non-InnoDB data in an incremental backup, use the --only-innodb option.

  You cannot use the --compress option together with the --incremental-with-redo-log-only option.

• --incremental-base=mode:argument

  Command-Line Format	--incremental-base=mode:argument
  Type	String

  With this option, the mysqlbackup retrieves the information needed to perform incremental backups from the metadata inside the backup directory rather than from the --start-lsn option. It saves you from having to specify an ever-changing, unpredictable LSN value when doing a succession of incremental backups. Instead, you specify a way to locate the previous backup directory through the combination of mode : argument in the option syntax. The alternatives are:

  • history:{last_backup | last_full_backup}

    The prefix history: followed by one of the two possible values:

    • last_backup: This makes mysqlbackup query the end_lsn value from the last successful non-TTS backup as recorded in the backup_history table of the server instance that is being backed up.

    • last_full_backup: This works similarly as the value last_backup, except that it makes mysqlbackup look for the last full backup that was taken and use it as the base backup, thus creating a differential backup .

    Note

    If the last full or partial backup made was a TTS backup, mysqlbackup skips it, and keeps searching the backup history until it finds the last non-TTS backup and then returns its end_lsn value.

  • dir:directory_path

    Advanced: You specify the prefix dir: followed by a directory path argument, which points to the previous directory backup. With the first incremental backup, you specify the directory holding the full directory backup; with the second incremental backup, you specify the directory holding the first incremental directory backup, and so on.

• --start-lsn=LSN

  Command-Line Format	--start-lsn=LSN
  Type	Numeric

  In an incremental backup, specifies the highest LSN value included in a previous backup. You can get this value from the output of the previous backup operation, or from the backup_history table's end_lsn column for the previous backup operation. Always used in combination with the --incremental option; not needed when you use the --incremental-base option; not recommended when you use the --incremental-with-redo-log-only mechanism for incremental backups.

  Note

  No binary log files are copied into the incremental backup if the --start-lsn option is used. To include binary log files for the period covered by the incremental backup, instead of --start-lsn, use the --incremental-base option, which provides the necessary information for mysqlbackup to ensure that no gap exists between binary log data included in the previous backup and the current incremental backup.

• --incremental-backup-dir=PATH

  Advanced: Specifies the location for data of an incremental directory backup. When creating or restoring an incremental directory backup, the option serves the same function as --backup-dir does for backups and restores in general, and the option can in fact be used interchangeably with --backup-dir for directory backups. See the description for --backup-dir for details.

  For an apply-incremental-backup operation, the option specifies the incremental backup directory whose data is used to update a directory backup specified by the --backup-dir option.

  Note

  Do not use this option with any operations for image backups, for which the option has no meaning.