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MySQL Enterprise Backup 8.4 User's Guide
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4.3.4 Making a Compressed Backup

To save disk space, you can compress InnoDB backup data files by using the --compress option of mysqlbackup. Compression lets you keep more sets of backup data on hand or save transmission time when sending the backup data to another server. Also, compression often results in faster backups because of reduced IO.

The backup compression feature works only for InnoDB tables. After the InnoDB tablespace files are compressed during backup, they receive the .ibz extension. To avoid wasting CPU cycles without saving additional disk space, --compress does not attempt to compress tables that were already-compressed on the server (see Creating Compressed Tables); nevertheless, such tablespace files are also saved with the .ibz extension inside the backup.


When there is unused space within an InnoDB tablespace file, the entire file is copied during an uncompressed backup. Perform a compressed backup to avoid the storage overhead for the unused space.

The binary log and relay log files are compressed and saved with the .bz extension when being included in a compressed backup.

You cannot use the --compress option for incremental backups created only with the redo log (i.e., with the --incremental-with-redo-log-only option).

You can also select the compression algorithm to use by the --compress-method option and, when using the ZLIB or LZMA compression algorithm, the level of compression by the --compress-level option. See Section 20.6, “Compression Options” for details.

This is a sample command for making a compressed single-file backup:

mysqlbackup --defaults-file=/home/dbadmin/my.cnf --compress --backup-image=backup.img backup-to-image

Advanced: This is a sample command for making a compressed directory backup:

mysqlbackup --defaults-file=/home/dbadmin/my.cnf --compress-method=zlib --compress-level=5 backup

This is a sample command for making a compressed and prepared directory backup:

mysqlbackup --defaults-file=/home/dbadmin/my.cnf --compress-method=zlib --compress-level=5 backup-and-apply-log


Compression ratio is low for encrypted InnoDB tables. Creating a compressed backup with a database containing many encrypted InnoDB tables is not recommended.


See the limitation that applies to compressed backups in Appendix B, Limitations of MySQL Enterprise Backup.