16.7 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. To restore an incremental backup, specify the --incremental and the --backup-dir option.

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

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

  Specifies that the associated backup, backup-to-image, copy-back-and-apply-log, or copy-back operation is incremental. When performing an incremental backup, there are two possible values for this option:

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

  • optimistic: mysqlbackup only scans for changed pages in the InnoDB data files that have been modified since the last backup and then saves them. In general, optimistic incremental backups are faster than full-scan ones when not many tables in the database have been modified; however a few restrictions apply to this feature. See Full-scan versus Optimistic Incremental Backup for details.

  Default: full-scan. The value for the option have no meaning when the option is used for restoring an incremental backup.

  During a backup, the option also requires the use of either the --incremental-base option or the --start-lsn option. Only InnoDB tables are backed up incrementally. By default, all non-InnoDB and .frm 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.

• --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.

  To use this option, you also need to specify the --incremental-base option or the --start-lsn option. Just like with the --incremental option, only InnoDB tables are backed up incrementally. By default, all non-InnoDB and .frm 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.

• --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 and argument in the option syntax. The alternatives are:

  • dir:directory_path

    You specify the prefix dir: followed by a directory path. The path argument points to the directory where the data from the previous backup is stored. With the first incremental backup, you specify the directory holding the full backup; with the second incremental backup, you specify the directory holding the first incremental backup, and so on.

  • 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: (For MySQL Enterprise Backup 4.1.5 and later) 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.

    Warning

    Do not use the history: mode if the previous backup was a full backup taken with the --no-connection option, which always turns off the recording of backup history and might cause errors for a subsequent incremental backup using this mode of the --incremental-base option.

• --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.