memcping: 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/memcping - from package: libmemcached-tools

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

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