[[backup-cluster-data]]
=== Back up a cluster's data
++++
<titleabbrev>Back up the data</titleabbrev>
++++

As with any software that stores data, it is important to routinely back up your
data. {es} replicas provide high availability during runtime; they enable you to
tolerate sporadic node loss without an interruption of service.

Replicas do not provide protection from catastrophic failure, however. For that,
you need a real backup of your cluster—a complete copy in case something goes
wrong.

To back up your cluster's data, you can use the <<modules-snapshots,snapshot API>>.

include::{es-repo-dir}/modules/snapshots.asciidoc[tag=snapshot-intro]

[TIP]
====
If your cluster has {es} {security-features} enabled, when you back up your data
the snapshot API call must be authorized.

The `snapshot_user` role is a reserved role that can be assigned to the user
who is calling the snapshot endpoint. This is the only role necessary if all the user
does is periodic snapshots as part of the backup procedure. This role includes
the privileges to list all the existing snapshots (of any repository) as
well as list and view settings of all indices, including the `.security` index.
It does *not* grant privileges to create repositories, restore snapshots, or
search within indices. Hence, the user can view and snapshot all indices, but cannot
access or modify any data.

For more information, see {stack-ov}/security-privileges.html[Security privileges]
and {stack-ov}/built-in-roles.html[Built-in roles].
====