cp: 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:

/bin/cp - from package: coreutils

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

On Debian possible default full paths are:

/bin/cp - from package: coreutils

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

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