ssm: 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/bin/ssm - from package: system-storage-manager

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

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