zfSnap: 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/sbin/zfSnap - from package: zfsnap

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