A connectivity test from the filestore configuration screen returns error of check your configuration.
Release : 17.2
Component : CA SERVICE CATALOG
To address, one must configure the SC Service to utilise a userid that has access privilege to access the NAS Drive and also has Admin rights over the SC Server. In this case, we will use a hypothetical user "NASAdmin", who has both rights to access the NAS Drive and also has Admin rights over the SC Server.
Update the SC 17x filestore to point to the NAS drive. Login to the SC 17x server with an account that can access the NAS drive and also has Admin rights over the SC Server, user "NASAdmin". Set the Service Catalog service to run as the "NASAdmin" user, then recycle the Service Catalog service. Test to see if SC works and attachments work (which they should)
Once this is done, you should be able to reboot the SC 17x server, then login to the SC 17x server as any user who has admin rights, besids the designated user who has both SC Server Admin rights and rights to access the NAS Drive, user "NASAdmin". The Service Catalog service should still be running as the "NASAdmin" user.
SC 17x NAS filestore should then be working without issue.
A similar solution may be applicable for Service Desk based installations as well if attachments are configured to store to a NAS based location.