drblsrv: 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/drblsrv - from package: drbl

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

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