Create a partial backup

xtrabackup supports taking partial backups when the innodb_file_per_table option is enabled. There are three ways to create partial backups:

1. matching the tables names with a regular expression

2. providing a list of table names in a file

3. providing a list of databases

Warning

Do not copy back the prepared backup.

Restoring partial backups should be done by importing the tables, not by using the –copy-back option. It is not recommended to run incremental backups after running a partial backup.

Although there are some scenarios where restoring can be done by copying back the files, this may lead to database inconsistencies in many cases and it is not a recommended way to do it.

For the purposes of this manual page, we will assume that there is a database named test which contains tables named t1 and t2.

Warning

If any of the matched or listed tables is deleted during the backup, xtrabackup will fail.

There are multiple ways of specifying which part of the whole data is backed up:

• Use the --tables option to list the table names

• Use the --tables-file option to list the tables in a file

• Use the --databases option to list the databases

• Use the --databases-file option to list the databases

The –-tables option

The first method involves the xtrabackup –tables option. The option’s value is a regular expression that is matched against the fully-qualified database name and table name using the databasename.tablename format.

To back up only tables in the test database, use the following command:

$ xtrabackup --backup --datadir=/var/lib/mysql --target-dir=/data/backups/ \
--tables="^test[.].*"

To back up only the test.t1 table, use the following command:

$ xtrabackup --backup --datadir=/var/lib/mysql --target-dir=/data/backups/ \
--tables="^test[.]t1"

The -–tables-file option

The --tables-file option specifies a file that can contain multiple table names, one table name per line in the file. Only the tables named in the file will be backed up. Names are matched exactly, case-sensitive, with no pattern or regular expression matching. The table names must be fully-qualified in databasename.tablename format.

$ echo "mydatabase.mytable" > /tmp/tables.txt
$ xtrabackup --backup --tables-file=/tmp/tables.txt

The --databases and -–databases-file options

The ` –databases` option accepts a space-separated list of the databases and tables to backup in the databasename[.tablename] format. In addition to this list, make sure to specify the mysql, sys, and

performance_schema databases. These databases are required when restoring the databases using xtrabackup –copy-back.

Note

Tables processed during the –prepare step may also be added to the backup even if they are not explicitly listed by the parameter if they were created after the backup started.

$ xtrabackup --databases='mysql sys performance_schema test ...'

The --databases-file option

The –databases-file option specifies a file that can contain multiple databases and tables in the databasename[.tablename] format, one element name per line in the file. Names are matched exactly, case-sensitive, with no pattern or regular expression matching.

Note

Tables processed during the –prepare step may also be added to the backup even if they are not explicitly listed by the parameter if they were created after the backup started.

The next step is to prepare the backup in order to restore it.