mountall: 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:

/sbin/mountall - from package: mountall

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

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