grml2usb: 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/grml2usb - from package: grml2usb

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

Error in other languages:
grml2usb: bevel nie gevind nie
grml2usb: comandă negăsită
grml2usb: comando não encontrado
grml2usb: commande introuvable
grml2usb: command not found
grml2usb: käsku ei ole
grml2usb: không tìm thấy lệnh
grml2usb: komanda nerasta
grml2usb: Kommando nicht gefunden.
grml2usb: kommandot finns inte
grml2usb: komut yok
grml2usb: nie znaleziono polecenia
grml2usb: níor aimsíodh an t-ordú
grml2usb: no se encontró la orden
grml2usb: no s'ha trobat l'ordre
grml2usb: opdracht niet gevonden
grml2usb: parancs nem található
grml2usb: perintah tidak ditemukan
grml2usb: príkaz nenájdený
grml2usb: příkaz nenalezen
grml2usb: команда не найдена
grml2usb: командата не е открита
grml2usb: 命令找不到
grml2usb: コマンドが見つかりません