stop: 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:

/sbin/stop - from package: upstart

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

On Debian possible default full paths are:

/sbin/stop - from package: upstart

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

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