Chapter 24

Monitoring System Performance (Tasks)

This chapter describes procedures for monitoring system performance by using the vmstat, iostat, df, and sar commands. This is a list of the step-by-step instructions in this chapter.

• "How to Display Virtual Memory Statistics (vmstat)"

• "How to Display System Event Information (vmstat -s)"

• "How to Display Swapping Statistics (vmstat -S)"

• "How to Display Cache Flushing Statistics (vmstat -c)"

• "How to Display Interrupts Per Device (vmstat -i)"

• "How to Display Disk Utilization Information (iostat)"

• "How to Display Extended Disk Statistics (iostat -xtc)"

• "How to Display Disk Space Information (df)"

• "How to Check File Access (sar -a)"

• "How to Check Buffer Activity (sar -b)"

• "How to Check System Call Statistics (sar -c)"

• "How to Check Disk Activity (sar -d)"

• "How to Check Page-Out and Memory (sar -g)"

• "How to Check Kernel Memory Allocation (sar -k)"

• "How to Check Interprocess Communication (sar -m)"

• "How to Check Page-In Activity (sar -p)"

• "How to Check Queue Activity (sar -q)"

• "How to Check Unused Memory (sar -r)"

• "How to Check CPU Utilization (sar -u)"

• "How to Check System Table Status (sar -v)"

• "How to Check Swapping Activity (sar -w)"

• "How to Check Terminal Activity (sar -y)"

• "How to Check Overall System Performance (sar -A)"

• "How to Set Up Automatic Data Collection"

What's New in Monitoring System Performance?

The vmstat command now includes all system interrupts in the faults-in column.

In previous Solaris releases, this column did not report clock device interrupts.

For more information, see vmstat(1M).

Displaying Virtual Memory Statistics (vmstat)

You can use the vmstat command to report virtual memory statistics and such information about system events as CPU load, paging, number of context switches, device interrupts, and system calls. The vmstat command can also display statistics on swapping, cache flushing, and interrupts.

The following table describes the fields in the vmstat output.

Table 24-1 Output From the vmstat Command

Category	Field Name	Description
procs		Reports on the following:
	r	The number of kernel threads in the dispatch queue
	b	The number of blocked kernel threads that are waiting for resources
	w	The number of swapped out LWPs that are waiting for processing resources to finish
memory		Reports on usage of real memory and virtual memory:
	swap	Available swap space
	free	Size of the free list
page		Reports on page faults and paging activity, in units per second:
	re	Pages reclaimed
	mf	Minor and major faults
	pi	Kbytes paged in
	po	Kbytes paged out
	fr	Kbytes freed
	de	Anticipated memory that is needed by recently swapped-in processes
	sr	Pages scanned by the page daemon (not currently in use). If sr does not equal zero, the page daemon has been running.
disk		Reports the number of disk operations per second, showing data on up to four disks
faults		Reports the trap/interrupt rates (per second):
	in	Interrupts per second
	sy	System calls per second
	cs	CPU context switch rate
cpu		Reports on the use of CPU time:
	us	User time
	sy	System time
	id	Idle time

For a more detailed description of this command, see vmstat(1M).