xtrabackup

xtrabackup is the main open-source tool for hot physical backups of MySQL, MariaDB and Percona Server, developed and maintained by Percona. Unlike mysqldump and mydumper — which produce logical dumps — it copies InnoDB data files directly on the filesystem while the database is running, with no downtime required.

How it works #

The process has two phases:

1. Backup: xtrabackup copies the InnoDB .ibd files and simultaneously reads the redo log to record all changes that happen during the copy. The result is a set of data files + a redo log that represents an inconsistent state of the database (the files were copied at slightly different moments) but a reconstructible one.
2. Prepare: before restore, xtrabackup --prepare performs a crash recovery applying the redo log to the data files, bringing them to a consistent state.

When it’s the best choice #

On datasets larger than ~100 GB, xtrabackup’s backup time is typically 5-10x faster than mysqldump and 2-4x faster than mydumper, because it skips INSERT regeneration entirely. The advantage is even more pronounced during restore, where a binary copy + crash recovery takes minutes compared to hours for a logical restore.

It’s the required choice when the maintenance window is tight, for pre-upgrade snapshots, and for lift-and-shift migrations to new storage.

Constraints to know #

• MyISAM tables are locked during their copy (FLUSH TABLES WITH READ LOCK): on databases with residual MyISAM this can cause application blocking for minutes
• The backup requires direct filesystem access on the MySQL server
• The restore requires replaying the redo log before the instance can start (--prepare phase)