When NFS is enabled here, the Tunable (fuse_remember) may be used to alleviate or solve instances of "NFS Stale File Handles" you might encounter with your NFS client.
In essence, (fuse_remember) tells an internal subsystem (named "fuse") how long to "remember" or "cache" file and directory information associated with user shares. When an NFS client attempts to access a file (or directory) on the server, and that file (or directory) name is not cached, then you could encounter "stale file handle".
The numeric value of this tunable is the number of seconds to cache file/directory name entries, where the default value of 330 indicates 5 1/2 minutes. There are two special values you may also set this to:
- 0 which means, do not cache file/directory names at all, and
- -1 which means cache file/directory names forever (or until array is stopped)
A value of 0 would be appropriate if you are enabling NFS but only plan to use it for disk shares, not user shares.
A value of -1 would be appropriate if no other timeout seems to solve the "stale file handle" on your client. Be aware that setting a value of -1 will cause the memory footprint to grow by approximately 108 bytes per file/directory name cached. Depending how much RAM is installed in your server and how many files/directories you access via NFS this may or may not lead to out-of-memory conditions.