Typical problems with media players

If you configure your computer to become an NFS-based media server which shares multimedia files for player devices (“media boxes”), you may encounter several problems because many media players use “cheap” NFS implementations which underly certain limitations.

A typical problem can be that the player might “see” the Mac and its NFS share on the network, but files or folders within the share stay invisible. This problem can have one or even several of the following causes:

The player does not understand spaces or special characters

Many players have problems to access shared files if either the path of the share (“/Volumes/My Media Files”) or files and folders within the share contain blanks (space characters) or other special characters (like colons, slashes, accented letters, etc.). If you suspect that this is the case for your player, perform the following steps:

1. Select the affected share entry in NFS Manager and delete it. Apply this change.
2. Use the Finder to rename the affected volume, folders, or files to the effect that all whitespace and special characters are removed. You may like to replace spaces by underscores (_), for example.
3. Re-create the share in NFS Manager and apply the change.

The player uses a user-level program to access the server

NFS usually requires that a privileged operating system process using privileged TCP/IP communication ports is used to mount a share. If a simple user program has permission to access NFS servers, this could be a major security problem because the NFS standard does not use passwords to identify users and their access permissions. If you suspect that your media player supports this unsafe mode of access only, perform the following steps:

1. Select the item NFS Server > Configuration in NFS Manager.
2. Ensure the tab item Features is open.
3. Remove the check marks Require mount requests to come from privileged ports and Require NFS requests to come from privileged ports if present.
4. Press the button Apply and restart the operating system.

The player uses the “root” user account to access the server

Media players usually require no user logins and have no multi-user operating systems. To emulate a Unix user account for accessing the NFS server, the media box might use the identification 0 which is equivalent to the omnipotent user account “root”. To avoid security problems, the root user has no access to NFS servers, because otherwise the root system administrator of one computer in the network would automatically gain total file access permissions for all NFS shares in the network. If you suspect that your media player supports this dangerous type of access only, perform the following steps:

1. Select the item NFS Server > Share Definitions in NFS Manager.
2. In the table of shares, select the entry which should be accessible from the media box.
3. Switch the pop-up button User Mapping: from Map “root” to unprivileged user (“nobody”) to the option Don’t map users.
4. Press the button Apply.

The player uses a user account which is unknown to the Mac

Instead of using the account “root” as outlined in the previous section, the media player may use a different user account which is either generally unknown or at least unknown to macOS because it is not registered in the Mac’s user account database. If you suspect that this is the problem, perform the following steps:

1. Select the shared folder in the Finder.
2. Select the menu item File > Get Info.
3. In the Info panel, ensure that the section Sharing & Permissions is open.
4. For the user group everyone, ensure that the setting Privilege is at least set to Read only. You may like to additionally use the feature Apply to enclosed items.

Ensure changes can take effect

Media players may also show the additional problem that they cannot disconnect (unmount) the share once the connection has been established. Access is kept open for an indeterminate time. This can cause the changes you may have made not to become effective immediately. If you want to make absolutely sure that server and player are actually using the current settings, this general approach is recommended:

1. Switch the player off before you make modifications.
2. Perform the changes as outlined in the aforementioned paragraphs.
3. Reboot the server.
4. Switch the player on again.