Configure xtrabackup¶
All the xtrabackup configuration is done through options, which behave
exactly like standard MySQL program options: they can be specified either at
the command-line, or through a file such as /etc/my.cnf.
The xtrabackup binary reads the [mysqld] and [xtrabackup] sections
from any configuration files, in that order. That is so that it can read its
options from your existing MySQL installation, such as the datadir or
some of the InnoDB options. If you want to override these, just specify them
in the [xtrabackup] section, and because it is read later, it will take
precedence.
You don’t need to put any configuration in your my.cnf. You can specify the options on the command-line. Normally, the only thing you may find convenient to place in the [xtrabackup] section
of your my.cnf file is the target_dir option. This options adds a default path to the
directory for backups.
The following is an example:
[xtrabackup]
target_dir = /data/backups/
This manual assumes you do not have any file-based configuration for xtrabackup and shows the command-line options.
Please see the option and variable reference for details on all the configuration options.
The xtrabackup binary does not accept exactly the same syntax in the
my.cnf file as the mysqld server binary does. For historical
reasons, the mysqld server binary accepts parameters with a
--set-variable=<variable>=<value> syntax, which xtrabackup does not
understand. If your my.cnf file has such configuration directives, you
should rewrite them in the --variable=value syntax.
System configuration and NFS volumes¶
The xtrabackup tool requires no special configuration on most systems.
However, the storage where the --target-dir is located
must behave properly when fsync() is called. In particular, we have noticed
that if you mount the NFS volume without the sync option the NFS
volume does not sync the data. As a result, if you back up to an NFS
volume mounted with the async
option, and then try to prepare the backup from a different server that also
mounts that volume, the data might appear to be corrupt. Use the
sync mount option to avoid this issue.
Get expert help¶
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