drbl-ssi-client-prepare: 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/share/drbl/sbin/drbl-ssi-client-prepare - from package: drbl

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

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