erl-guestfs: command not found

Have You tried accessing the binary with the full path?

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/bin/erl-guestfs - from package: erlang-guestfs

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