mpdcleanup: 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/mpdcleanup - from package: mpich2

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

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