mrtg2pcp: 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/bin/mrtg2pcp - from package: pcp-import-mrtg2pcp

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

On Debian possible default full paths are:

/usr/bin/mrtg2pcp - from package: pcp-import-mrtg2pcp

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

Error in other languages:
mrtg2pcp: bevel nie gevind nie
mrtg2pcp: comandă negăsită
mrtg2pcp: comando não encontrado
mrtg2pcp: commande introuvable
mrtg2pcp: command not found
mrtg2pcp: käsku ei ole
mrtg2pcp: không tìm thấy lệnh
mrtg2pcp: komanda nerasta
mrtg2pcp: Kommando nicht gefunden.
mrtg2pcp: kommandot finns inte
mrtg2pcp: komut yok
mrtg2pcp: nie znaleziono polecenia
mrtg2pcp: níor aimsíodh an t-ordú
mrtg2pcp: no se encontró la orden
mrtg2pcp: no s'ha trobat l'ordre
mrtg2pcp: opdracht niet gevonden
mrtg2pcp: parancs nem található
mrtg2pcp: perintah tidak ditemukan
mrtg2pcp: príkaz nenájdený
mrtg2pcp: příkaz nenalezen
mrtg2pcp: команда не найдена
mrtg2pcp: командата не е открита
mrtg2pcp: 命令找不到
mrtg2pcp: コマンドが見つかりません