nfsd(8) System Manager's Manual nfsd(8)
NAME
nfsd - The remote NFS compatible server
SYNOPSIS
/usr/sbin/nfsd [-t num_tcpthreads] [-u num_udpthreads]
The following form of the nfsd command is not recommended and is supported only for backward compatibility:
/usr/sbin/nfsd [numthreads]
FLAGS
Specifies a number of TCP server threads (per RAD) to spawn. A value of 8 is recommended as a start. Specifies a number of UDP server
threads (per RAD) to spawn. A value of 8 is recommended as a start.
DESCRIPTION
The nfsd daemon runs on a server machine to service NFS requests from client machines. The daemon spawns a number of server threads that
process NFS requests from client machines. At least one server thread must be running for a machine to operate as a server.
There are two types of server threads: a server thread that processes NFS requests sent using TCP and a server thread that processes NFS
requests sent using UDP. This is necessary because the kernel paths for UDP and TCP NFS messages are different. The -t option specifies
the number of TCP threads to run and the -u option specifies the number of UDP threads to run.
On systems that support Cache Coherent NUMA, the number of threads is per Resource Affinity Domain (RAD). As you add RADs, the NFS server
will automatically scale by creating additional threads. NFS requests are processed by a particular RAD based on the file being accessed;
this confines cached information about a file to a single RAD for efficiency. See numa_intro(3) for more information on the NUMA architec-
ture.
If you use the SysMan Menu to configure NFS, it sets the default at 8 UDP and 8 TCP threads. However, a user can have any number of TCP
and UDP nfsd threads running up to a maximum of 128 threads. The optimal number of TCP server threads and UDP server threads depends on
many factors. See nfsiod(8) for more information.
The server threads are implemented as kernel threads; they are part of Process ID 0, not the nfsd process. The ps axml command displays
idle server threads under PID 0. Idle threads will be waiting on nfs_udp_wait or nfs_tcp_wait. Therefore, if 16 server threads are config-
ured, only one nfsd process is displayed in the output from the ps command, although 16 server threads are available to handle NFS
requests.
Files that are larger than 2 gigabytes are exported as 2 gigabyte files when accessed by NFS Version 2. NFS Version 2 is a 32-bit proto-
col, therefore, the size and offset fields are 32-bit quantities (on Alpha UFS they are 64-bit quantities). Use caution when accessing
files larger than 2 gigabytes from NFS clients.
EXAMPLES
In the following example, 16 threads are run (8 for TCP and 8 for UDP): nfsd -t 8 -u 8
FILES
Specifies the command path Specifies the file for logging startup errors (before the server threads are started). Specifies the file for
logging NFS errors (after the server threads are started).
RELATED INFORMATION
Commands: mount(8), mountd(8), nfsconfig(8), nfsstat(8), portmap(8)
System calls: nfssvc(2) delim off
nfsd(8)