Which two methods can back up a Cisco DNA Center Assurance database?

Cisco DNA Center (DNAC) Assurance database backups are critical for disaster recovery. DNAC supports backing up to a remote server using Secure Copy Protocol (SCP) or Secure File Transfer Protocol (SFTP), which are secure methods for transferring files over a network. It also supports Network File System (NFS) shares, allowing DNAC to mount a remote directory and store backups there. These methods ensure the backup data is stored externally, separate from the DNAC appliance itself, providing resilience against appliance failure. Backing up to a "local server" is not a distinct, supported method; DNAC is an appliance, and backups are external. "Bare metal server" and "non-Linux server" are too generic and don't specify a supported backup protocol or storage type.