pm-pmu: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/lib64/pm-utils/bin/pm-pmu - from package: pm-utils

You may install the required package with command yum install {package}

Error in other languages:
pm-pmu: bevel nie gevind nie
pm-pmu: comandă negăsită
pm-pmu: comando não encontrado
pm-pmu: commande introuvable
pm-pmu: command not found
pm-pmu: käsku ei ole
pm-pmu: không tìm thấy lệnh
pm-pmu: komanda nerasta
pm-pmu: Kommando nicht gefunden.
pm-pmu: kommandot finns inte
pm-pmu: komut yok
pm-pmu: nie znaleziono polecenia
pm-pmu: níor aimsíodh an t-ordú
pm-pmu: no se encontró la orden
pm-pmu: no s'ha trobat l'ordre
pm-pmu: opdracht niet gevonden
pm-pmu: parancs nem található
pm-pmu: perintah tidak ditemukan
pm-pmu: príkaz nenájdený
pm-pmu: příkaz nenalezen
pm-pmu: команда не найдена
pm-pmu: командата не е открита
pm-pmu: 命令找不到
pm-pmu: コマンドが見つかりません