Where to keep your JCS data
The JCS databases must either be on a local disk, or on a Server Message Block (SMB) share served by a device on the local network. This is a limitation of the JET database technology used by JCS.
The JCS databases cannot be stored in services such as Dropbox, OneDrive or Azure Files.
Regardless of where you store your data you must keep regular backups. Please refer to the UK National Cyber Security Centre guidance for small businesses.
Local Disk
If you only have one JCS user you can simply store your JCS data on the C:\ drive.
Shared using Windows Folder Sharing
If you are running JCS on a few computers you can store the data on one computer running Windows and share it using Windows File and Folder Sharing to the other computers in your office. This would mean the computer storing the JCS data has to be turned on for the other computers to be able to use JCS.
You can also store your JCS data on a Windows Server and share it using an SMB share to your computers.
Note that the connection between the JCS application and your JCS Databases is sensitive to network reliability and latency so that connection must not be made over the internet and your network should be wired rather than using Wi-Fi.
Network Attached Storage (NAS) Appliance
We have customers that keep their JCS databases on a NAS device in their office, shared over SMB. As this is not supported by Microsoft we are not able to fully support it either. We will provide best effort support for this environment and are not aware of any issues with this.