compiz: 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/compiz - from package: compiz

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

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