phyllis@bcsaic.UUCP (08/02/86)
I'm examining system performance on an Ultrix 1.2 system. The output from 'vmstat' includes 'active virtual pages' (avm) and 'free pages' (fre). Can someone explain to me how to interpret this information? I've seen values ranging from 313/5164 (avm/fre) to 5219/2677. Obviously a higher avm means more memory activity; but, beyond such obvious interpretations, I don't know what to make of these numbers. My appreciation in advance.... -- Phyllis Melvin Boeing Advanced Technology Center ...uw-beaver!uw-june!bcsaic!phyllis
chris@umcp-cs.UUCP (Chris Torek) (08/04/86)
In article <633@bcsaic.UUCP> phyllis@bcsaic.UUCP writes: >I'm examining system performance on an Ultrix 1.2 system. The output >from 'vmstat' includes 'active virtual pages' (avm) and 'free pages' >(fre). Can someone explain to me how to interpret this information? `Active virtual memory' is the sum of the virtual sizes of all `active' processes. Here an active process is defined as one that is running, waiting for `fast' I/O (e.g., disk read), or asleep but not for more than twenty seconds. `Free pages' are those pages that are not allocated to any process. The machine begins paging whenever free space gets low enough (`low enough' depends on your configuration, and on any kernel fixes you may have installed). The `sweep rate' (sr) goes up, and page outs (po) and reclaims (re) begin to occur. If the deficit (de) becomes nonzero the machine is `desperate' for real memory. If the paging rate is `high enough', or the system is `desperate', it will begin swapping. -- In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 1516) UUCP: seismo!umcp-cs!chris CSNet: chris@umcp-cs ARPA: chris@mimsy.umd.edu