pwrkap_aggregate: 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 Debian possible default full paths are:

/usr/bin/pwrkap_aggregate - from package: pwrkap

You may install the required package with command apt-get install {package}

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