Expandable departmental cloud server systems

A modular and expandable office system, comprising:

• one or more client units;
• a base unit (BU) having a predetermined hardware design acting as a base device to provide server operation;
• one or more interchangeable modular hardware network devices having the predetermined hardware design to operate in conjunction with the base unit to expand service to the one or more client units, the network device selected from a group consisting of:
• a second network unit having the predetermined hardware design coupled to the first unit and serving as a mirror unit under software configuration, wherein the second unit is added as a mirror unit (MU) to back up the first unit as a server;
• a third network unit having the predetermined hardware design coupled to the first unit and serving as an expansion unit (EU) under software configuration, wherein the third unit is added as needed to increase client capacity;
• and
• a fourth network unit having the predetermined hardware coupled to the first unit and located at a remote location from the first network unit, and with software configuration, acts as a remote disaster recovery (RU) unit,
• wherein each of the BU, MU, EU and RU comprises interchangeable modular hardware with software configurable personalities or roles and each unit includes modules to handle user information, user management, file resource to replicate disk or designate a folder as private or public, user chat, system configuration and equipment topology configuration, email management, and network settings, wherein a graphical user interface (GUI) allows personalization without IT expertise for each unit as either a BU, MU, EU, or an RU, wherein the GUI allows interchangeable modular hardware to be added by a user without information technology (IT) background to perform file resource operation process, system configuration process, email management process, network settings process, user management process and chatting process.