This Knowledgebase article provides information about how File Server is not supported in a Microsoft Windows workgroup environment.
Neverfail for File Server installed in Windows Workgroups does not support the creation of users after Neverfail has been installed. For this reason, Neverfail does not recommend its use outside of a domain environment. Any user created post Neverfail install will be unable to access files or folders after a switchover or failover to the Secondary server.
Additionally, Neverfail for File Server will not be able to provide a high availability solution exactly as described in product documentation, due to the security features of Microsoft Windows when operating in a workgroup environment.
In a workgroup environment, user SIDs are stored on the server where they are created, unlike a domain, where this information is stored in Active Directory. Neverfail Heartbeat does not replicate the user SID database between active and passive servers. For this reason, a user account created on the active server will not exist on the passive. Therefore, any users created after installation of Neverfail Heartbeat in a workgroup environment will not be able to access the information on the passive server as they did previously on the active server following a switchover or failover.
It is not possible to recreate these users on the passive server, as Microsoft Windows specifies that they must have the same SID in order to access the same information. When a user account is created in this way, Microsoft Windows will create a different SID. Please see Microsoft Windows documentation on user SIDs for further information if required.
Microsoft Windows Workgroup environment