vm_stat

The vm_stat utility displays virtual memory statistics. Unlike implementations of vm_stat in other Unix systems, it does not default to continuous display. Instead, it displays accumulated statistics.

To obtain a continuous display, specify an interval argument (in seconds), as in vm_stat 1. Figure 8-3 shows the output of vm_stat with no arguments, and Figure 8-4 shows the output of vm_stat 1. Table 8-4 describes the information that vm_stat displays (the item numbers correspond to the callouts in both figures).

vm_stat displaying accumulated statistics
Figure 8-3. vm_stat displaying accumulated statistics
vm_stat’s continuous output
Figure 8-4. vm_stat’s continuous output
Table 8-4. Information displayed by vm_stat

Item number

Accumulated mode

Continuous mode

Description

1
Pages free
free

Total free pages

2
Pages active
active

Total pages in use that can be paged out

3
Pages inactive
inac

Total inactive pages

4
Pages wired down
wire

Total pages wired into memory (cannot be paged out)

5
Translation Faults
faults

Number of times vm_fault has been called

6
Pages copy-on-write
copy

Number of faults that resulted in a page being copied

7
Pages zero filled
zerofill

Number of pages that have been zero-filled

8
Pages Reactivated
reactive

Number of pages reclassified from inactive to active

9
Pageins
pagein

Number ...

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