Concurrency and Backups

You can run backups concurrently with most other database operations.

The exception are:

No metadata changes can occur while the catalog store is backed up.
No commands that issue checkpoints or DBCC can be run during backup.

Be aware, however, that transactions that have not committed when you start a backup are not backed up. If a system or media failure occurs during backup, you cannot restore uncommitted transactions.

Once a backup is started, you cannot execute a CHECKPOINT command.