Compressed Backup¶
Percona XtraBackup supports compressed backups: a local or streaming backup can be compressed or decompressed with xbstream.
Creating Compressed Backups¶
In order to make a compressed backup you’ll need to use the xtrabackup –compress option:
$ xtrabackup --backup --compress --target-dir=/data/compressed/
The xtrabackup --compress uses the qpress tool that you can install via
the percona-release package configuration tool as follows:
$ sudo percona-release enable tools
$ sudo apt update
$ sudo apt install qpress
Note
Enable the repository: percona-release enable-only tools release. If you intend to use Percona XtraBackup in combination with the upstream MySQL Server, you only need to enable the tools repository: percona-release enable-only tools.
If you want to speed up the compression you can use the parallel compression, which can be enabled with xtrabackup –compress-threads option. Following example will use four threads for compression:
$ xtrabackup --backup --compress --compress-threads=4 \
--target-dir=/data/compressed/
Output should look like this
...
170223 13:00:38 [01] Compressing ./test/sbtest1.frm to /tmp/compressed/test/sbtest1.frm.qp
170223 13:00:38 [01] ...done
170223 13:00:38 [01] Compressing ./test/sbtest2.frm to /tmp/compressed/test/sbtest2.frm.qp
170223 13:00:38 [01] ...done
...
170223 13:00:39 [00] Compressing xtrabackup_info
170223 13:00:39 [00] ...done
xtrabackup: Transaction log of lsn (9291934) to (9291934) was copied.
170223 13:00:39 completed OK!
Preparing the backup¶
Before you can prepare the backup you must uncompress all the files.
Percona XtraBackup has implemented xtrabackup --decompress option
that can be used to decompress the backup.
$ xtrabackup --decompress --target-dir=/data/compressed/
Note
xtrabackup --parallel can be used with xtrabackup --decompress option to decompress multiple files simultaneously.
Percona XtraBackup does not automatically remove the compressed files. In
order to clean up the backup directory, use the
xtrabackup --remove-original option. If the files not removed
they are not copied or moved to the datadir if
xtrabackup --copy-back or xtrabackup --move-back are used.
When the files are uncompressed you can prepare the backup with the
xtrabackup --prepare option:
$ xtrabackup --prepare --target-dir=/data/compressed/
Check for a confirmation message:
InnoDB: Starting shutdown...
InnoDB: Shutdown completed; log sequence number 9293846
170223 13:39:31 completed OK!
Now the files in /data/compressed/ are ready to be used by the server.
Restoring the backup¶
xtrabackup has a xtrabackup --copy-back option, which performs the
restoration of a backup to the server’s datadir:
$ xtrabackup --copy-back --target-dir=/data/backups/
The option copies all the data-related files back to the server’s datadir,
determined by the server’s my.cnf configuration file. Check the last line of the output for a success message:
170223 13:49:13 completed OK!
Verify the file permissions after copying the data back. You may need to adjust the permissions. For example, the following command changes the owner of the file location:
$ chown -R mysql:mysql /var/lib/mysql
Now that the datadir contains the restored data. You are ready to start
the server.
Contact us
For free technical help, visit the Percona Community Forum.
To report bugs or submit feature requests, open a JIRA ticket.
For paid support and managed or consulting services , contact Percona Sales.
