>> Swap usage on Linux always seems a little tricky to me. Should my
>> goal on a web server be zero swap usage, meaning the attached graph
>> should show no green lines at all if I'm doing it right?
>>
>
> No. You want things that aren't in use to be swapped, like memory
> leaks and such. You don't want things that will be used to be
> swapped.
Does this look OK? It looks to me like heavy swapping in and out with
plenty of free memory (minus buffers/cache).
# vmstat 1 20
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
r b swpd free buff cache si so bi bo in cs us sy id wa st
0 1 155308 71328 29200 2437260 1 0 127 63 0 0 48
1 50 1 0
0 1 155308 44444 29204 2465164 0 0 27772 0 1483 1236 1
1 74 24 0
2 2 155480 32904 29220 2476392 0 172 33684 172 4166 2790 44
2 30 24 0
4 0 155828 30332 29220 2479756 0 348 41388 348 5319 1884 76
2 1 21 0
1 1 156184 37668 29244 2470752 0 356 28960 424 5033 3299 53
2 15 29 0
0 2 156412 32912 29264 2477364 0 228 30976 252 2909 2516 14
2 56 29 0
2 5 156640 29372 29400 2480328 0 228 23180 344 3949 3156 32
2 35 31 0
1 4 157072 36372 29624 2469924 0 432 28032 488 4120 3289 50
2 10 37 0
2 4 157260 37372 29812 2466036 0 188 12188 316 3789 2540 54
1 7 38 0
2 3 157260 30236 29912 2467672 0 0 16372 48 3730 2077 57
2 8 34 0
2 3 157304 29684 28940 2459688 24 44 10892 44 4271 2808 44
2 11 43 0
5 2 157824 36448 28372 2440176 4 520 13036 620 4796 3185 56
2 10 33 0
2 3 157928 34552 28516 2437032 4 104 19620 148 4446 4108 48
3 15 35 0
2 6 157928 38620 28444 2385828 436 0 4808 136 4615 2851 39
5 6 51 0
3 5 157928 36936 28604 2377112 732 0 8072 84 4773 2970 64
2 0 34 0
5 7 157928 39068 28832 2375944 40 0 2040 492 4877 3341 71
2 1 26 0
3 4 157928 81820 28984 2376868 188 0 19320 0 5122 6990 66
5 0 30 0
# free -h
total used free shared buffers cached
Mem: 3.9G 3.8G 41M 88M 20M 2.4G
-/+ buffers/cache: 1.4G 2.4G
Swap: 1.0G 154M 869M
- Grant
