memcp: 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 CentOS possible default full paths are:

/usr/bin/memcp - from package: libmemcached10
/usr/bin/memcp - from package: libmemcached

You may install the required package with command yum install {package}

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