MySQL Enterprise Backup User's Guide (Version 8.4.5)
For an overview on backup compression, see Section 4.3.4, “Making a Compressed Backup”.
Create backup in compressed format. For a regular backup,
among all the storage engines supported by MySQL, only data
files of the InnoDB format are compressed, and they bear the
.ibz extension after the compression.
Similarly, for a single-image backup, only data files of the
InnoDB format inside the backup image are compressed. 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 together with the
--incremental-with-redo-log-only
option.
Default: compression is disabled.
| Command-Line Format | --compress-method=ALGORITHM |
|---|---|
| Type | Enumeration |
| Default Value | lz4 |
| Valid Values |
|
Specifies the algorithm for backup compression, or enables support for InnoDB transparent page compression. The supported arguments for the option and the algorithms they represent are:
lz4: LZ4 r109. Out of the three
compression algorithms that are supported, this is the
most efficient one, typically taking the shortest
backup and restore times with the lowest CPU cost. See
lz4—Extremely Fast Compression algorithm
for more details, including a comparison with other
compression algorithms.
lzma: LZMA 9.20. Out of the three
supported compression algorithms, this typically
provides the highest compression ratio; but it is also
far more expensive in terms of CPU cost than the other
two options. Thus we do not recommend this for active
systems, but only for off-hour or inactive database
servers, or where I/O rates are extremely low.
zlib: ZLIB v1.2.3. This is in
between the other two supported compression algorithms
in terms of both speed and compression ratio. ZLIB was
the only compression algorithm available for MySQL Enterprise Backup
versions prior to 3.10.
punch-hole: (
Enables support for
transparent
page compression for InnoDB tables for
directory backups, which means that when the target
platform for the mysqlbackup backup
or restore operation supports hole punching,
mysqlbackup keeps the punched holes
in the page-compressed InnoDB files it transfers.
Limitations: The feature is NOT supported in the following cases, for which punched holes are removed from the InnoDB files:
For single-file backups.
For TTS, incremental, compressed, or encrypted backups.
When a backup is not created in a file system (for example, when cloud storage is used to save the backup), or when the file system does not support sparse files.
For those pages of InnoDB data files that are
modified by the redo log in an
apply-log operation.
When the feature is enabled but hole punching fails, mysqlbackup issues a warning message after the operation is completed; for example:
WARNING: "Punch hole" operation failed.
Or:
WARNING: InnoDB datafiles in the backup are larger than in the source because of missing sparse file support.
A backup can be taken with
--compress-method=punch-hole
and then be restored later without using the feature;
the reverse is also true: a backup taken without using
--compress-method=punch-hole
can be restored later with the feature.
punch-hole is a special argument
with the
--compress-method option
for supporting transparent page compression.
--compress-method=punch-hole
is ignored when used together with any other
mysqlbackup compression options.
none: No compression.
Default: lz4. Explicitly specifying a value other than
punch-hole for the option through a
configuration file or command line automatically enables the
--compress option.
| Command-Line Format | --compress-level=LEVEL |
|---|---|
| Type | Numeric |
| Default Value | 1 |
| Minimum Value | 0 |
| Maximum Value | 9 |
Specifies the level of compression, ranging from
“0” to “9”: “0
”disables compression; “1” is fastest
compression, and “9” is highest (and slowest)
compression. The option is only meaningful for compression
using the ZLIB or LZMA algorithm; it is ignored when any
other algorithms are selected by the
--compress-method option.
Default: 1 (lowest and fastest compression). Explicitly
specifying a non-zero value through a configuration file or
command line automatically enables the
--compress option.
When used with the
extract operation,
uncompresses files that are extracted from a compressed
single-file backup (the option is not required
when the
--src-entry
option is used).