1 The following is a demonstration of the dvmstat program, 2 3 4 Here we run dvmstat to monitor all processes called "find". In another 5 window, a "find /" command is run, 6 7 # dvmstat -n find 8 re maj mf fr epi epo api apo fpi fpo sy 9 0 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 0 0 0 0 0 0 0 11 6336 0 372 0 0 0 0 0 0 0 22255 12 1624 0 0 0 0 0 0 0 0 0 5497 13 2292 0 0 0 0 0 0 0 0 0 7715 14 13064 0 0 0 0 0 0 0 0 0 43998 15 7972 168 0 0 0 0 0 0 168 0 38361 16 468 636 0 0 0 0 0 0 636 0 13774 17 376 588 0 0 0 0 0 0 588 0 10723 18 80 636 0 0 0 0 0 0 656 0 11078 19 48 772 0 0 0 0 0 0 812 0 9841 20 16 1028 0 0 0 0 0 0 1056 0 10752 21 0 1712 0 0 0 0 0 0 1740 0 12176 22 4 1224 0 0 0 0 0 0 1236 0 9024 23 24 The output above is spectacular! When the find command is first run, 25 it begins be reading data from the file cache, as indicated by the "re" 26 reclaims, and a lack of "fpi" filesystem page ins. 27 28 Eventually the find command travels to places which are not cached, we can 29 see the "re" value drops, and both the "maj" major faults and "fpi" values 30 increase. This transition from cache hits to file system activity is 31 very clear from the above output. 32 33 34 35 Here we run a dvmstat to examine the PID 3778, 36 37 # dvmstat -p 3778 38 re maj mf fr epi epo api apo fpi fpo sy 39 0 0 0 0 0 0 0 0 0 0 0 40 0 0 0 0 0 0 0 0 0 0 0 41 24 28 0 0 0 0 0 0 28 0 109 42 4 148 16 0 0 0 0 0 148 0 1883 43 16 412 384 0 0 0 0 0 412 0 21019 44 0 0 0 0 0 0 0 0 0 0 3 45 0 0 0 0 0 0 0 0 0 0 221 46 0 0 0 0 0 0 0 0 0 0 0 47 0 0 0 0 0 0 0 0 0 0 84 48 0 0 0 0 0 0 0 0 0 0 0 49 50 Here we can see the statistics for that process only. 51 52 53 54 The following runs the date command through dvmstat, 55 56 # dvmstat date 57 Sun Jun 12 17:44:24 EST 2005 58 re maj mf fr epi epo api apo fpi fpo sy 59 16 0 208 0 0 0 0 0 0 0 38 60 61 The values above are for the date command only. 62 63 64 65 Now we run dvmstat on a tar command. Here we tar around 50Mb of files, 66 so the command takes around 20 seconds to complete, 67 68 # dvmstat tar cf backup.tar DTrace 69 re maj mf fr epi epo api apo fpi fpo sy 70 20 256 304 0 8 0 0 0 352 0 621 71 4540 56 896 0 0 0 0 0 4636 0 1005 72 4432 12 644 0 0 0 0 0 4384 0 906 73 680 180 136 0 8 0 0 0 1056 0 502 74 2328 60 468 0 0 0 0 0 2296 0 592 75 1300 380 272 0 0 0 0 0 1704 0 1095 76 2816 72 560 0 0 0 0 0 2940 0 709 77 4084 40 416 0 0 0 0 0 4220 0 894 78 2764 4 276 0 0 0 0 0 2700 0 566 79 1824 96 328 0 0 0 0 0 2072 0 556 80 3408 80 392 0 20 0 0 0 3496 0 857 81 2804 92 552 0 4 0 0 0 2924 0 741 82 1344 16 272 0 0 0 0 0 1376 0 289 83 3284 52 520 0 12 0 0 0 3260 0 743 84 4832 200 812 0 0 0 0 0 5292 0 1276 85 11052 56 2200 0 0 0 0 0 8676 0 2326 86 5256 328 1020 0 8 0 0 0 4404 0 1725 87 re maj mf fr epi epo api apo fpi fpo sy 88 404 340 72 0 64 0 0 0 536 0 1135 89 90 Great! Activity from the tar command such as "fpi"s can be clearly seen. 91 92
Indexes created Fri Apr 24 00:22:58 UTC 2026