I'm trying to track down a repeated CPU spike on one of my filers. About every 30 seconds, sysstat will show the CPU usage at or near 100%. There is no pattern to this other than the length of time between spikes.

What are some common things I should look for? What commands might help me track down the culprit?

Here's an example:

96% 86 733 0 819 378 1054 36 0 0 0 30 100% 0% - 2% 95% 62 609 0 671 357 819 1106 16 0 0 30 100% 0% - 15% 32% 80 597 0 677 532 363 1352 0 0 0 30 100% 0% - 17% 9% 47 750 0 797 1209 715 2960 0 0 0 30 96% 0% - 37% 11% 36 777 0 813 1310 1597 5564 16 0 0 30 97% 0% - 55% 5% 102 876 0 978 940 1837 296 0 0 0 30 99% 0% - 11% 2% 59 165 0 224 370 403 16 0 0 0 30 100% 0% - 1% 15% 27 504 0 531 53 228 744 7108 0 0 30 100% 29% T 25% 11% 45 827 0 872 1222 559 56 68 0 0 30 100% 7% : 4% 1% 81 102 0 183 367 764 0 0 0 0 30 100% 0% - 0% 1% 39 79 0 118 38 166 32 16 0 0 30 100% 0% - 2% 3% 32 345 0 377 128 216 768 0 0 0 30 96% 0% - 15% 9% 159 756 0 915 310 1122 6048 0 0 0 30 98% 0% - 72% 10% 371 543 0 914 1764 2896 2660 16 0 0 30 98% 0% - 34% 1% 127 85 0 212 1122 729 16 0 0 0 30 99% 0% - 1% 1% 24 67 0 91 183 179 4 0 0 0 30 100% 0% - 1% 2% 248 101 0 349 69 177 56 16 0 0 30 100% 0% - 2% 2% 144 104 0 248 100 476 0 0 0 0 30 100% 0% - 0% 18% 18 156 0 174 383 297 2345 5569 0 0 30 100% 30% T 29% 5% 38 350 0 388 102 239 1376 2300 0 0 30 100% 18% : 21% 6% 374 262 0 636 148 582 3504 0 0 0 30 94% 0% - 39% 5% 80 236 0 316 231 1251 4724 0 0 0 30 94% 0% - 41% 4% 0 266 0 266 396 2253 3128 16 0 0 30 97% 0% - 27% 1% 37 97 0 134 245 609 0 0 0 0 30 100% 0% - 0% 1% 53 83 0 136 155 275 0 0 0 0 30 100% 0% - 0% 1% 76 82 0 158 57 151 48 16 0 0 30 100% 0% - 1% 2% 57 169 0 226 38 343 8 0 0 0 30 100% 0% - 1% 2% 179 167 0 346 170 311 28 0 0 0 30 99% 0% - 3% 8% 50 310 0 360 205 670 6068 16 0 0 30 97% 0% - 54% 11% 130 406 0 536 530 1192 4612 3260 0 0 30 98% 31% T 60% 8% 27 768 0 795 184 1086 3748 92 0 0 30 98% 10% : 35% 43% 64 500 0 564 190 949 3836 16 0 0 30 100% 0% - 21% 92% 46 677 0 723 1178 1455 3383 0 0 0 30 100% 0% - 21%