ocs-iso: 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/ocs-iso - from package: clonezilla

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