Backup Data Stored In An InnoDB Storage Engine

• The InnoDB storage engine has support for transactions and automatic crash recovery.

• If the InnoDB data files do not contain consistent data due to a crash, InnoDB reads its logs and finds in them the list of pending committed and non-committed transactions that have not been flushed to the data files.
  • InnoDB automatically rolls back those transactions that were not committed.
  • InnoDB flushes to its data files those that were committed.
  • Information about the recovery process is written to the MySQL error log.

• If MySQL disk data is not available after a restart, MySQL will fail to start because blocks on the disk data are no longer readable.
  • In this case, it is necessary to reformat the disk, or install a new disk.
  • Then it is necessary to recover MySQL data from backups.
    • which means that backups must already have been made.

What is a good backup strategy?

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© 2007 John Michael Pierobon

Notes