A Network File System (NFS) server can share directory hierarchies in its local file systems with remote client systems over an IP-based network. After an NFS server exports a directory, NFS clients mount this directory if they have been granted permission to do so. The directory appears to the client systems as if it were a local directory. NFS centralizes storage provisioning and can improves data consistency and reliability.
Oracle Linux 7 supports the following versions of the NFS protocol:
NFSv3 relies on Remote Procedure Call (RPC) services, which are controlled by the
rpcbind
service. rpcbind
responds to requests for an
RPC service and sets up connections for the requested service. In addition, separate services
are used to handle locking and mounting protocols. Configuring a firewall to cope with the
various ranges of ports that are used by all these services can be complex and error
prone.
NFSv4 does not use rpcbind
as the NFS server itself listens on TCP port
2049 for service requests. The mounting and locking protocols are also integrated into the
NFSv4 protocol, so separate services are also not required for these protocols. These
refinements mean that firewall configuration for NFSv4 is no more difficult than for a service
such as HTTP.