kttcp(4) [netbsd man page]

KTTCP(4)						   BSD Kernel Interfaces Manual 						  KTTCP(4)

NAME

     kttcp -- kernel support for testing network throughput

SYNOPSIS

     pseudo-device kttcp

DESCRIPTION

     This driver provides kernel support for testing network throughput from the perspective of the kernel.  It is similar in spirit to the clas-
     sic ttcp network benchmark program, the main difference being that with kttcp, the kernel is the source and sink of the data.

     Testing like this is useful for a few reasons:

     1.   This allows us to know what kind of performance we can expect from network applications that run in the kernel space, such as the NFS
	  server or the NFS client.  These applications don't have to move the data to/from userspace, and so benchmark programs which run in
	  userspace don't give us an accurate model.

     2.   Since data received is just thrown away, the receiver is very fast.  This can provide better exercise for the sender at the other end.

     3.   Since the NetBSD kernel currently uses a run-to-completion scheduling model, kttcp provides a benchmark model where preemption of the
	  benchmark program is not an issue.

SEE ALSO

     pkgsrc/benchmarks/kttcp, pkgsrc/benchmarks/ttcp

BSD
								 December 2, 2006							       BSD

NFSIOD(8)						    BSD System Manager's Manual 						 NFSIOD(8)

NAME

     nfsiod -- local NFS asynchronous I/O server

SYNOPSIS

     nfsiod [-n num_servers]

DESCRIPTION

     The nfsiod utility controls the maximum number of nfsiod kernel processes which run on an NFS client machine to service asynchronous I/O
     requests to its server.  Having nfsiod kernel processes improves performance but is not required for correct operation.

     The option is as follows:

     -n      Specify how many processes are permitted to be started.

     Without an option, nfsiod displays the current settings.  A client should allow enough number of processes to handle its maximum level of
     concurrency, typically four to six.

     If nfsiod detects that the running kernel does not include NFS support, it will attempt to load a kernel module containing NFS code, using
     kldload(2).  If this fails, or no NFS module was available, nfsiod exits with an error.

EXIT STATUS

     The nfsiod utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

     nfsstat(1), kldload(2), nfssvc(2), mountd(8), nfsd(8), rpcbind(8)

HISTORY

     The nfsiod utility first appeared in 4.4BSD.

     Starting with FreeBSD 5.0, the utility no longer starts daemons, but only serves as a vfs loader and sysctl(3) wrapper.

BSD
								 December 26, 2009							       BSD