SQL basic availability groups
A basic availability group supports a failover environment containing a single database. SQL basic availability groups are configured the same way as SQL Always-On High Availability groups, with the following differences:
- Limit of two replicas (primary and secondary).
- No read access on secondary replica.
- No backups on secondary replica.
- No integrity checks on secondary replicas.
- Support for one availability database.
- Basic availability groups cannot be upgraded to advanced availability groups. The group must be dropped and readded to a group that contains servers running only SQL Server 2016 Enterprise Edition.
- Basic availability groups are only supported for Standard Edition servers.
- Basic availability groups cannot be part of a distributed availability group.
For multi-subnet environments, see Enable SQL Always On multi-subnet failover.