VM_STAT(1)

NAME
vm_stat - show Mach virtual memory statistics

SYNOPSIS
vm_stat [ [-c count] interval]

DESCRIPTION
vm_stat displays Mach virtual memory statistics. If the optional interval is specified, then vm_stat will display the statistics every interval seconds. In this case, each line of output displays the change in each statistic (an interval count of 1 displays the values per second). However, the first line of output following each banner displays the system-wide totals for each statistic. If a count is provided, the command will terminate after count intervals. The following values are displayed:

Pages free
    the total number of free pages in the system.

Pages active
    the total number of pages currently in use and pageable.

Pages inactive
    the total number of pages on the inactive list.

Pages speculative
    the total number of pages on the speculative list.

Pages throttled
    the total number of pages on the throttled list (not wired but not pageable).

Pages wired down
    the total number of pages wired down. That is, pages that cannot be paged out.

Pages purgeable
    the total number of purgeable pages.

Translation faults
    the number of times the "vm_fault" routine has been called.

Pages copy-on-write
    the number of faults that caused a page to be copied (generally caused by copy-on-write faults).

Pages zero filled
    the total number of pages that have been zero-filled on demand.

Pages reactivated
    the total number of pages that have been moved from the inactive list to the active list (reactivated).

Pages purged
    the total number of pages that have been purged.

File-backed pages
    the total number of pages that are file-backed (non-swap)

Anonymous pages
    the total number of pages that are anonymous

Uncompressed pages
    the total number of pages (uncompressed) held within the compressor

Pages used by VM compressor:
    the number of pages used to store compressed VM pages.

Pages decompressed
    the total number of pages that have been decompressed by the VM compressor.

Pages compressed
    the total number of pages that have been compressed by the VM compressor.

Pageins
    the total number of requests for pages from a pager (such as the inode pager).

Pageouts
    the total number of pages that have been paged out.

Swapins
    the total number of compressed pages that have been swapped out to disk.

Swapouts
    the total number of compressed pages that have been swapped back in from disk.

If interval is not specified, then vm_stat displays all accumulated statistics along with the page size.