Making a Compressed Backup

In order to make a compressed backup, use the --compress option along with the --backup and --target-dir options. By default --compress uses the quicklz compression algorithm.

$ xtrabackup --backup --compress --target-dir=/data/backup

You can also use the lz4 compression algorithm by setting :option:--compress to lz4.

$ xtrabackup --backup --compress=lz4 --target-dir=/data/backup

If you want to speed up the compression you can use the parallel compression, which can be enabled with --compress-threads option. The following example uses four threads for compression.

$ xtrabackup --backup --compress --compress-threads=4 --target-dir=/data/backup

Output should look like this

...

[01] Compressing ./imdb/comp_cast_type.ibd to /data/backup/imdb/comp_cast_type.ibd.qp
[01]        ...done
...
130801 11:50:24  xtrabackup: completed OK

Preparing the backup

Before you can prepare the backup you’ll need to uncompress all the files with qpress (which is available from Percona Software repositories). You can use the following one-liner to uncompress all the files:

$ for bf in `find . -iname "*\.qp"`; do qpress -d $bf $(dirname $bf) && rm $bf; done

If you used the lz4 compression algorithm change this script to search for *.lz4 files:

$ for bf in `find . -iname "*\.lz4"`; do lz4 -d $bf $(dirname $bf) && rm $bf; done

You can decompress the backup by using the --decompress option:

$ xtrabackup --decompress --target-dir=/data/backup/

See also

What is required to use the –decompress option effectively?
--decompress

When the files are uncompressed you can prepare the backup with the --apply-log-only option:

$ xtrabackup --apply-log-only --target-dir=/data/backup/

You should check for a confirmation message:

130802 02:51:02  xtrabackup: completed OK!

Now the files in /data/backup/ is ready to be used by the server.

Note

Percona XtraBackup doesn’t automatically remove the compressed files. In order to clean up the backup directory users should remove the *.qp files.

Restoring the backup

Once the backup has been prepared you can use the --copy-back to restore the backup.

$ xtrabackup --copy-back --target-dir=/data/backup/

This will copy the prepared data back to its original location as defined by the datadir variable in your my.cnf.

After the confirmation message, you should check the file permissions after copying the data back.

130802 02:58:44  xtrabackup: completed OK!

You may need to adjust the file permissions. The following example demonstrates how to do it recursively by using chown:

$ chown -R mysql:mysql /var/lib/mysql

Now, your data directory contains the restored data. You are ready to start the server.