derdump: 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/bin/derdump - from package: libnss3-tools

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

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