System information

The following RPC processes facilitate NFS services:
rp c.mo untd
This process is used by an NFS server to process MO UNT requests from NFSv2 and NFSv3
clients. It checks that the requested NFS share is currently exported by the NFS server, and
that the client is allowed to access it. If the mount request is allowed, the rpc.mountd server
replies with a Success status and provides the Fi l e-Hand l e for this NFS share back to
the NFS client.
lo ckd
l o ckd is a kernel thread which runs on both clients and servers. It implements the Network
Lock Manager (NLM) protocol, which allows NFSv2 and NFSv3 clients to lock files on the
server. It is started automatically whenever the NFS server is run and whenever an NFS file
system is mounted.
rp c.st at d
This process implements the Network Status Monitor (NSM) RPC protocol, which notifies NFS
clients when an NFS server is restarted without being gracefully brought down. rpc. statd
is started automatically by the nfsl o ck service, and does not require user configuration.
This is not used with NFSv4.
rp c.rq u o t ad
This process provides user quota information for remote users. rpc. rq uo tad is started
automatically by the nfs service and does not require user configuration.
rp c.id map d
rpc. i d mapd provides NFSv4 client and server upcalls, which map between on-the-wire
NFSv4 names (which are strings in the form of user@ domain) and local UIDs and GIDs.
For i d mapd to function with NFSv4, the /etc/i dmapd . co nf file must be configured. This
service is required for use with NFSv4, although not when all hosts share the same DNS
domain name. Refer to the knowledge base article
https://access.redhat.com/site/solutions/130783 when using a local domain.
9.2. pNFS
Support for Parallel NFS (pNFS) as part of the NFS v4.1 standard is available as of Red Hat
Enterprise Linux 6.4. The pNFS architecture improves the scalability of NFS, with possible
improvements to performance. That is, when a server implements pNFS as well, a client is able to
access data through multiple servers concurrently. It supports three storage protocols or layouts:
files, objects, and blocks.
To enable this functionality, use one of the following mount options on mounts from a pNFS-enabled
server:
-o mi no rversi o n= 1
or
-o v4 . 1
After the server is pNFS-enabled, the nfs_l ayo ut_nfsv4 1_fi l es kernel is automatically loaded
on the first mount. Use the following command to verify the module was loaded:
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