To begin with OS: IBM AIX
#oslevel
5.3.0.0
lparstat
#lparstat
System configuration: type=Shared mode=Uncapped smt=On lcpu=12 mem=12288 psize=16 ent=3.00
%user %sys %wait %idle physc %entc lbusy app vcsw phint
----- ----- ------ ------ ----- ----- ------ --- ----- -----
0.4 0.3 3.4 95.9 0.02 0.7 28.3 10.67 560694523 37167085
vmstat
System configuration: lcpu=12 mem=12288MB ent=3.00
kthr memory page faults cpu
----- ----------- ------------------------ ------------ -----------------------
r b avm fre re pi po fr sr cy in sy cs us sy id wa pc ec
6 1 1156074 636649 0 0 0 0 0 0 3604 189043 19464 61 38 1 0 4.82 160.6
6 0 1148587 644228 0 0 0 0 0 0 3032 195003 16715 61 38 1 0 5.04 168.0
5 0 1159487 633233 0 0 0 0 0 0 3357 184922 17515 61 38 1 0 4.77 159.2
4 0 1149753 643033 0 0 0 0 0 0 3670 185761 19294 59 39 1 0 4.78 159.4
5 0 1158086 634631 0 0 0 0 0 0 2758 187931 17119 61 38 1 0 4.72 157.4
So the lpar has 6 processing units, with SMT on, and that is why vmstat is listing 12 lcpus. The issue is result that vmstat fetches varies with what we see from nmon statistics we gather from this system. vmstat always show that the idle % (id) is 1 - indicating CPU is 99% utilized. But when we look at plotted nmon information, that is not the case, on an average CPU is utilized only up to 60% - including usr,sys,wait &idle Is vmstat inconsistent under CPUS with SMT on? or am interpreting the vmstat incorrectly?