multistrap: 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/multistrap - from package: multistrap

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

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