virtualenvwrapper.sh: 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/virtualenvwrapper.sh - from package: python-virtualenvwrapper

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

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