Syncplify Server! concepts

Background reading before the how to pages:

• High availability (HA) concepts: what an active active cluster needs, with and without a load balancer.
• Licensing and license codes: perpetual licenses, maintenance plans, code formats and what happens when hardware changes.
• Why PGP is the wrong tool for at rest encryption, and what Syncplify Server! uses instead.
• Understanding FTP and its variants: plain FTP, implicit FTPS, FTPES, active and passive mode.
• SFTP and SCP: the two file transfer protocols of SSH-2 and how they relate to exec and shell.