.\" Copyright (c) 1997, Apple Computer, Inc. All rights reserved. .\" .Dd August 13, 1997 .Dt VM_STAT 1 .Os "Mac OS X" .Sh NAME .Nm vm_stat .Nd show Mach virtual memory statistics .Sh SYNOPSIS .Nm vm_stat .Op Ar interval .Sh DESCRIPTION .Nm vm_stat displays Mach virtual memory statistics. If the optional .Ar interval is specified, then .Nm vm_stat will display the statistics every .Ar interval seconds. In this case, each line of output displays the change in each statistic (an .Ar 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. The following values are displayed: .Bl -tag -width indent .It Pages free the total number of free pages in the system. .It Pages active the total number of pages currently in use and pageable. .It Pages inactive the total number of pages on the inactive list. .It Pages wired down the total number of pages wired down. That is, pages that cannot be paged out. .It Translation faults the number of times the "vm_fault" routine has been called. .It Pages copy-on-write the number of faults that caused a page to be copied (generally caused by copy-on-write faults). .It Pages zero filled the total number of pages that have been zero-filled on demand. .It Pages reactivated the total number of pages that have been moved from the inactive list to the active list (reactivated). .It Pageins the number of requests for pages from a pager (such as the inode pager). .It Pageouts the number of pages that have been paged out. .El .Pp If .Ar interval is not specified, then .Nm vm_stat displays all accumulated statistics along with the page size and the object cache performance.