The folders you specify as a default backup folder, a progressive backup folder, and as an additional database folder must be valid.
•If you specify a folder on a local volume, you must do the following:
•Ensure that the folder has permissions set correctly so that FileMaker Server can read and write to the folder.
•macOS: a local folder must be owned by the FileMaker Server user account (or in the group fmsadmin).
•If you specify a folder on a remote volume, you must do the following:
•When you install FileMaker Server, specify a FileMaker Server user account other than the default account. Ensure that this account has sufficient permissions to read and write the folder on the remote volume.
Windows: If the FileMaker Server user account is a Windows domain account, disable User Access Control (UAC) and restart FileMaker Server. See Windows Help and Support.
•macOS: To use a remote volume, make sure the remote volume is mounted and accessible before FileMaker Server starts.
•You can't specify a remote volume for the backup folders.
•Specify the folder as an absolute path:
•Windows: The path you enter must start with filewin:/ and end with a slash (/).
For example, filewin:/driveLetter:/folderName/
If you are using a network volume, the path you enter must have the server name.
For example, filewin:/serverName/shareName/folderName/
You can use Windows Explorer or the DOS command prompt to map network drives and remotely access folders on a computer by specifying the Universal Naming Convention (UNC) names.
•macOS: The path you enter must start with filemac:/ and end with a slash (/).
For example, filemac:/volumeName/folderName/
To use a network volume, the networked drive must be mounted and the FileMaker Server user account must be a member of the daemon group.
•The folder path cannot contain any characters or words reserved by the operating system. For example, the folder path cannot contain com1 in Windows. In macOS the folder path cannot contain a colon (:) character.
•The default backup folder and progressive backup folder cannot be a parent or a subfolder of the default database folder, the additional database folder, or the Scripts folder. The additional database folder cannot be a parent or a subfolder of the default database folder, the backup folder, or the Scripts folder. See Database and backup folder settings.
See the FileMaker Knowledge Base.