oarmonitor: 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/sbin/oarmonitor - from package: oar-server

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

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