NFS Server Performance and Tuning Guide for Sun Hardware

Central Processor Units

This section explains how to determine CPU usage and provides guidelines for configuring CPUs in NFS servers.

Determining CPU Usage

To get 30 second averages, type mpstat 30 at the % prompt.

The following screen is displayed:

system% mpstat 30
CPU minf mjf xcal  intr ithr  csw icsw migr smtx  srw syscl  usr sys  wt idl
  0    6   0    0   114   14   25    0    6    3    0    48    1   2  25  72
  1    6   0    0    86   85   50    0    6    3    0    66    1   4  24  71
  2    7   0    0    42   42   31    0    6    3    0    54    1   3  24  72
  3    8   0    0     0    0   33    0    6    4    0    54    1   3  24  72

The mpstat 30 command reports statistics per processor. Each row of the table represents the activity of one processor. The first table summarizes all activities since the system was last booted. Each subsequent table summarizes activity for the preceding interval. All values are rates (events per second).

Review the following data in the mpstat output (see Table 4-2 ):

Table 4-2 Ouput of the mpstat Command


`usr`	Percent user time
`sys`	Percent system time (can be caused by NFS processing)
`wt`	Percent wait time (treat as for idle time)
`idl`	Percent idle time

If sys is greater than 50 percent, increase CPU power to improve NFS performance.

Table 4-2 describes guidelines for configuring CPUs in NFS servers.

Table 4-3 Guidelines for Configuring CPUs in NFS Servers


If	Then
Your environment is predominantly attribute-intensive, and you have one to three medium-speed Ethernet or Token Ring networks.	A uniprocessor system is sufficient. For smaller systems, the UltraServer 1, SPARCserver 2, or SPARCserver 5 systems have sufficient processor power.
Your environment is predominantly attribute-intensive and you have between 4 to 60 medium-speed Ethernet or Token Ring networks.	Use an UltraServer 2, SPARCserver 10, or SPARCserver 20 system.
You have larger attribute-intensive environments and SBus and disk expansion capacity is sufficient.	Use multiprocessor models of the UltraServer 2, SPARCserver 10 or the SPARCserver 20 systems.
You have larger attribute-intensive environments.	Use dual-processor systems such as: - SPARCserver 10 system Model 512 - SPARCserver 20 system - SPARCserver 1000 or 1000E system - Ultra Enterprise 3000, 4000, 5000, or 6000 system - SPARCcenter 2000/2000E system Either the 40 MHz/1Mbyte or the 50MHz/2 Mbyte module work well for an NFS work load in the SPARCcenter 2000 system. You will get better performance from the 50 MHz/2Mbyte module.
Your environment is data-intensive and you have a high-speed network.	Configure one SuperSPARC processor per high-speed network (such as FDDI).
Your environment is data-intensive and you must use an Ethernet connection due to cabling restrictions.	Configure one SuperSPARC processor for every four Ethernet or Token Ring networks.
Your environment is a pure NFS installation.	You do not need to configure additional processors beyond the recommended number on your server(s).
Your servers perform tasks in addition to NFS processing.	Add additional processors to increase performance significantly.