memcdump: 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/memcdump - from package: libmemcached-tools

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

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