pyrasite: 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/pyrasite - from package: pyrasite

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

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