NFS Performance Tuning for HP-UX 11.0 and 11i Systems

nfs performance tuning for hp-ux 11.0 and 11i systems page 45

Notes:

Page 45July 22, 2002

nfsd

Why are more nfsds launched than

configured in NUM_NFSD?

• Number of NFS/UDP daemons must be equally divisible

by the number of CPUs due to processor affinity

• If NFS/TCP is enabled – one additional nfsd is launched

Example – 8 CPU system, NFS/TCP enabled, 100 nfsds

requested – you will actually get 105 nfsds

100 (requested nfsds) / 8 (CPUs) = 12.5

13 (rounded) * 8 = 104 + 1 (TCP) = 105

There are several factors that determine the number of nfsd processes that get

launched on any given HP-UX 11.0 or 11i NFS server:

• The number of daemons requested on the nfsd command line or specified

via the NUM_NFSD variable in the /etc/rc.config.d/nfsconf file

• The number of CPUs in the server

• Whether NFS/TCP is enabled on the server

The number of NFS/UDP daemons must be a number equally divisible by the

number of CPUs because the kernel enables processor affinity for the nfsds at

initialization time. The affinity mode is advisory, meaning that the daemons can

run on a CPU other than the one they were originally bound to. The kernel

automatically increases the number of nfsds to the next number which is evenly

divisible by the number of CPUs.

If NFS/TCP is enabled, an additional nfsd daemon is launched to manage the TCP

connection establishment and teardown functions.