ash: 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:

/bin/ash - from package: ash

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

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