1N/AThe following is a demonstration of the dvmstat program,
1N/AHere we run dvmstat to monitor all processes called "find". In another
1N/Awindow, a "find /" command is run,
1N/A re maj mf fr epi epo api apo fpi fpo sy
1N/A 0 0 0 0 0 0 0 0 0 0 0
1N/A 0 0 0 0 0 0 0 0 0 0 0
1N/A 6336 0 372 0 0 0 0 0 0 0 22255
1N/A 1624 0 0 0 0 0 0 0 0 0 5497
1N/A 2292 0 0 0 0 0 0 0 0 0 7715
1N/A 13064 0 0 0 0 0 0 0 0 0 43998
1N/A 7972 168 0 0 0 0 0 0 168 0 38361
1N/A 468 636 0 0 0 0 0 0 636 0 13774
1N/A 376 588 0 0 0 0 0 0 588 0 10723
1N/A 80 636 0 0 0 0 0 0 656 0 11078
1N/A 48 772 0 0 0 0 0 0 812 0 9841
1N/A 16 1028 0 0 0 0 0 0 1056 0 10752
1N/A 0 1712 0 0 0 0 0 0 1740 0 12176
1N/A 4 1224 0 0 0 0 0 0 1236 0 9024
1N/AThe output above is spectacular! When the find command is first run,
1N/Ait begins be reading data from the file cache, as indicated by the "re"
1N/Areclaims, and a lack of "fpi" filesystem page ins.
1N/AEventually the find command travels to places which are not cached, we can
1N/Asee the "re" value drops, and both the "maj" major faults and "fpi" values
1N/Aincrease. This transition from cache hits to file system activity is
1N/Avery clear from the above output.
1N/AHere we run a dvmstat to examine the PID 3778,
1N/A re maj mf fr epi epo api apo fpi fpo sy
1N/A 0 0 0 0 0 0 0 0 0 0 0
1N/A 0 0 0 0 0 0 0 0 0 0 0
1N/A 24 28 0 0 0 0 0 0 28 0 109
1N/A 4 148 16 0 0 0 0 0 148 0 1883
1N/A 16 412 384 0 0 0 0 0 412 0 21019
1N/A 0 0 0 0 0 0 0 0 0 0 3
1N/A 0 0 0 0 0 0 0 0 0 0 221
1N/A 0 0 0 0 0 0 0 0 0 0 0
1N/A 0 0 0 0 0 0 0 0 0 0 84
1N/A 0 0 0 0 0 0 0 0 0 0 0
1N/AHere we can see the statistics for that process only.
1N/AThe following runs the date command through dvmstat,
1N/A Sun Jun 12 17:44:24 EST 2005
1N/A re maj mf fr epi epo api apo fpi fpo sy
1N/A 16 0 208 0 0 0 0 0 0 0 38
1N/AThe values above are for the date command only.
1N/ANow we run dvmstat on a tar command. Here we tar around 50Mb of files,
1N/Aso the command takes around 20 seconds to complete,
1N/A re maj mf fr epi epo api apo fpi fpo sy
1N/A 20 256 304 0 8 0 0 0 352 0 621
1N/A 4540 56 896 0 0 0 0 0 4636 0 1005
1N/A 4432 12 644 0 0 0 0 0 4384 0 906
1N/A 680 180 136 0 8 0 0 0 1056 0 502
1N/A 2328 60 468 0 0 0 0 0 2296 0 592
1N/A 1300 380 272 0 0 0 0 0 1704 0 1095
1N/A 2816 72 560 0 0 0 0 0 2940 0 709
1N/A 4084 40 416 0 0 0 0 0 4220 0 894
1N/A 2764 4 276 0 0 0 0 0 2700 0 566
1N/A 1824 96 328 0 0 0 0 0 2072 0 556
1N/A 3408 80 392 0 20 0 0 0 3496 0 857
1N/A 2804 92 552 0 4 0 0 0 2924 0 741
1N/A 1344 16 272 0 0 0 0 0 1376 0 289
1N/A 3284 52 520 0 12 0 0 0 3260 0 743
1N/A 4832 200 812 0 0 0 0 0 5292 0 1276
1N/A 11052 56 2200 0 0 0 0 0 8676 0 2326
1N/A 5256 328 1020 0 8 0 0 0 4404 0 1725
1N/A re maj mf fr epi epo api apo fpi fpo sy
1N/A 404 340 72 0 64 0 0 0 536 0 1135
1N/AGreat! Activity from the tar command such as "fpi"s can be clearly seen.