AIX check cpu usage

This is a useful check. FWIW... At a customer site where they use this check for AIX 6.1, and noticed an issue when the vmstat samples look similar to the following: 10 0 2750794 5040508 0 0 0 0 0 0 75 7806 2920 6 1 93 0 0.34 11.4 8 0 2750684 5040617 0 0 0 0 0 0 345 5356 2780 0 1 99 0 0.08 2.6 8 0 2750686 5040615 0 0 0 0 0 0 53 4138 2640 0 0 99 0 0.04 1.3 11 0 2750686 5040615 0 0 0 0 0 0 8 4358 2965 0 0 99 0 0.04 1.3 Note that the first field in the second and third sample above have a leading whitespace character in "r" column. That appears to throw off the field identification and calculation. You can see the wild inconsistencies, if you loop the check from command line: OK - CPU usage at 75.25% CRITICAL - CPU usage at 100% CRITICAL - CPU usage at 100% OK - CPU usage at 50.5% CRITICAL - CPU usage at 100% CRITICAL - CPU usage at 100% OK - CPU usage at 50.5% OK - CPU usage at 1% OK - CPU usage at 50.75% CRITICAL - CPU usage at 100% And then compare that to a simple "vmstat 1": 4 0 2691885 5098619 0 0 0 0 0 0 30 3364 2164 0 0 99 0 0.03 1.0 6 0 2691885 5098619 0 0 0 0 0 0 29 3595 2239 1 0 99 0 0.05 1.6 0 0 2693761 5096742 0 0 0 0 0 0 126 9301 2525 17 1 82 0 0.84 28.1 85 0 2693762 5096741 0 0 0 0 0 0 51 3564 2223 0 0 99 0 0.04 1.5 35 0 2693762 5096741 0 0 0 0 0 0 19 3509 2129 0 0 99 0 0.04 1.2 32 0 2693762 5096741 0 0 0 0 0 0 8 3251 2152 0 0 99 0 0.03 0.8 31 0 2693697 5096806 0 0 0 0 0 0 20 3765 2153 1 0 98 0 0.09 3.0 0 0 2693918 5096584 0 0 0 0 0 0 151 6348 2315 5 1 94 0 0.29 9.8 Note that the CPU is typically > 90+% idle... To test a fix to this, I used "xargs -l" to sanitize the vmstat output, accounted to the actual number of fields, and then adjusted the "strip" portion for whitespace: # diff orig_check_aix_cpu.pl new_check_aix_cpu.pl 30c30 open(PS, "/usr/bin/vmstat 1 4 | egrep -v '[a-z,A-Z]|-' |egrep '[0-9]' | xargs -l |") || return 1; 32c32 (undef,undef,undef,undef,undef,undef,undef,undef,undef,undef,undef,undef,undef,undef,undef,$idle,undef,undef,undef) = split(/[s+n]+/); When I run the modified script in a loop, the results looks a bit more sane: OK - CPU usage at 1% OK - CPU usage at 1% OK - CPU usage at 1.75% OK - CPU usage at 1% OK - CPU usage at 4% OK - CPU usage at 1% OK - CPU usage at 2% OK - CPU usage at 1% YMMV...

bla@bla:~/temp$ vmstat procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu---- r b swpd free buff cache si so bi bo in cs us sy id wa 1 0 0 1163264 73420 1191884 0 0 59 23 270 450 4 2 94 0 bla@bla:~/temp$ ./check_aix_cpu.pl -w 20 -c 40 CRITICAL - CPU usage at 100%