gnt-storage: 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/gnt-storage - from package: ganeti

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