A Microsoft SharePoint farm consists of front-end Web servers and Microsoft SQL servers.
A front-end Web server is a host where SharePoint services are running. Some front-end Web servers may be identical to each other (for example, the front-end Web servers that run a Web server). You do not have to back up all identical front-end Web servers but only unique ones.
To protect SharePoint databases, you need to back up all of the Microsoft SQL servers and all of the unique Web Front End servers belonging to the farm. The backups should be done with the same schedule. This is needed because the configuration database must be synchronized with other databases. For example, if the content database contains the data about a site while the latest backup of the configuration database does not, the site will be orphaned after the configuration database is recovered.
If you have Acronis Backup Advanced, the easiest way to back up a SharePoint farm is to create a centralized backup plan as described in the "Creating a centralized backup plan" section, or use the Back up now feature as described in the "Back up now" section. In Acronis Backup, you must specify the identical schedule when creating a backup plan for every server belonging to the farm.