drbl-clean-dhcpd-leases: 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/drbl-clean-dhcpd-leases - from package: drbl

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

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