From The Open Source Backup Wiki (Amanda, MySQL Backup, BackupPC)
ZRM for MySQL organizes backups in sets. Each backup set can have compression or no compression option set.
Compression reduces the space required for storing backup images. Compression of most databases is useful but compression of tables using ARCHIVE storage engine is not useful because they are already compressed.
Each backup set can use any compression utility available on the server running ZRM for MySQL. The default compression program used is gzip. You can specify other programs that meet the following criteria.
It should be able to compress data from standard input and put back the compressed data to standard output. The compression program should also support the -d command line option to uncompress data. Program wrapper scripts might be required if there is a different option to uncompress or if compression and uncompress are different programs.
When remote MySQL servers are backed up, data compression does not reduce network bandwidth as the data is compressed on the machine running ZRM for MySQL. It only reduces the amount of space required to store the backup.
Backup compression is set by mysql-zrm.conf parameters. These parameters can be specified globally or to specific backup set.
- compress: Enables/Disables compression for the backup set. Default is no compression. Value of 1 means backup data will be compressed. Value 0 means no compression.
- compress-plugin: Full path to the utility for compression. If this parameter is not specified, gzip is used.
- compress-mysqldump-onthefly : Logical backups can be compressed on the fly in memory. Value of 1 will enable this option.