vmstat does not return an average for last line

[babbottscott]

This script purports to check cpu state over a specified interval, but uses vmstat to check state, then assumes the last line gives an average. Suggest changing from vmstat to sar. To overcome the problem of processing float output in bash, can use bc to process.

Linux avg cpu over interval:

  Linux)
    CPU_REPORT=`/usr/bin -u $INTERVAL_SEC $NUM_REPORT | tail -1`
    CPU_USER=`echo $CPU_REPORT | awk '{ print $3 }'`
    CPU_SYSTEM=`echo $CPU_REPORT | awk '{ print $5 }'`
    CPU_IOWAIT=`echo $CPU_REPORT | awk '{ print $6 }'`
    CPU_IDLE=`echo $CPU_REPORT | awk '{ print $8 }'`

Floating point comparison for bash/bc

float_ge() {
  [ $(echo "$1 >= $2" | /usr/bin/bc) -eq 1 ]
}

Floating point comparison in use:

if float_ge "${CPU_IOWAIT}" "${IO_CPU_C}" || float_ge "${CPU_USER}" "${U_CPU_C}" || float_ge "${CPU_SYSTEM}" "${S_CPU_C}";
then
...

Requires packages sysstat and bc to fully implement