Re: ICH6M SATA Controller, SATA2 NCQ disk and high iowait CPU time

Tejun Heo
2006-12-01T00:50:58Z

gary.czek wrote:
> "vmstat 5" when system is really slow shows following:
>
> procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
> r b swpd free buff cache si so bi bo in cs us sy id wa
> 0 9 285904 3044 832 42088 75 46 247 98 484 746 5 2 80 13
> 0 4 285560 3628 692 43724 686 71 913 418 952 1651 18 3 0 79
> 0 3 285000 3616 688 43100 822 15 1431 766 939 1761 16 4 0 80
> 0 3 284372 3612 700 42344 703 0 1234 43 941 1697 18 3 7 72
> 1 2 284012 3176 580 42800 406 0 1054 74 834 1602 15 4 36 45
> 0 3 283820 3888 824 40044 413 23 1102 95 865 1767 17 3 0 80
> 0 1 286364 3904 900 41508 63 540 1023 629 928 1646 15 3 0 82
> 0 2 287500 4884 1120 44840 388 338 1606 431 902 1670 13 4 0 83
> 0 10 291148 3104 1296 46088 396 827 923 877 917 1521 10 3 0 87
> 0 3 292952 3728 1492 47524 259 474 730 606 889 1754 15 2 0 84
> 0 2 294960 3540 1588 47488 633 632 970 678 863 1630 12 2 0 86
> 0 2 297444 3828 1676 46496 648 674 774 735 886 1906 14 2 0 84
> 0 3 298184 3616 1684 46420 593 290 759 331 844 1792 12 3 0 85
> 0 5 297836 3852 1508 43576 632 168 990 229 814 1605 10 1 0 88

Your machine is thrashing. Working set size is over the available
memory and pages are continuously getting dropped and then brought back.
Run top and press 'M' after the list showed up. It will show who are
consuming all the memory. Adding 1G should solve the problem but just
another 256M will make a big difference too.

--
tejun