ocs-update-initrd: 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/sbin/ocs-update-initrd - from package: clonezilla

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

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