My ZFS system hits a high load average every week during its scrub. Here is what top looks like after I pressed i and then S:
last pid: 42049; load averages: 3.78, 3.26, 3.42 up 18+13:47:14 11:43:01
220 processes: 3 running, 216 sleeping, 1 waiting
CPU: 7.5% user, 0.0% nice, 12.8% system, 1.2% interrupt, 78.5% idle
Mem: 765M Active, 236M Inact, 8667M Wired, 17M Cache, 3284M Buf, 22G Free
Swap: 8192M Total, 2404K Used, 8190M Free
PID USERNAME THR PRI NICE SIZE RES STATE C TIME WCPU COMMAND
11 root 8 155 ki31 0K 128K CPU7 7 3331.6 625.59% idle
0 root 204 -8 0 0K 3264K - 4 105.6H 68.07% kernel
32775 10837 1 87 0 88584K 49864K CPU3 3 5:32 49.27% postgres
12 root 31 -76 - 0K 496K WAIT 0 999:45 9.33% intr
13 root 3 -8 - 0K 48K - 5 866:23 9.13% geom
6 root 4 -8 - 0K 80K soldel 2 776:06 7.67% zfskern
32774 dan 1 23 0 27708K 4568K select 7 0:49 6.05% pg_restore
8992 10837 1 22 0 75792K 45768K select 0 1:15 3.17% postgres
8994 10837 1 20 0 75792K 13000K zio->i 5 0:14 0.20% postgres
42033 dan 1 52 0 6276K 720K wait 0 0:00 0.20% make
36815 dan 1 20 0 16560K 2920K CPU4 7 0:00 0.10% top
41840 dan 1 52 0 6276K 752K wait 0 0:00 0.10% make
42037 dan 1 52 0 14504K 1888K wait 7 0:00 0.10% sh
41841 dan 1 32 0 14504K 1892K wait 5 0:00 0.10% sh
42032 dan 1 32 0 14504K 1900K wait 3 0:00 0.10% sh
42049 dan 1 45 0 21724K 9860K zio->i 4 0:00 0.00% cc1plus
42048 dan 1 52 0 9916K 1536K wait 3 0:00 0.00% g++
There are a few other things going on. A Bacula regression test for one.
