How the pseudo-fs in NFSv4 affects mountpoints
NFSv4 uses a pseudo-fs (file system) as an entry point into your storage system for determining mountpoints. A pseudo-fs allows you to use one port for security, rather than several. All NFSv4 servers support the use of a pseudo-fs.
Enabling or disabling NFSv4.0
You can enable or disable NFSv4.0 by modifying the nfs.v4.enable option. This allows file access for clients using the NFSv4.0 protocol. By default, NFSv4.0 is disabled.
Flushing the name server database cache
You can use the nfs nsdb flush command to clear specific entries or all entries from the name server database (NSDB) cache. This removes outdated information from the cache after you made changes.
Differences in NFS user and group ID formats
NFSv3 handles user and group IDs as 32-bit numeric values. NFSv4 handles user and group IDs by default as strings in the form of user_name@domain_name. However, NFSv4 clients can also specify user and group IDs as numeric strings, which Data ONTAP can handle two different ways.