sgpio: 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:

/sbin/sgpio - from package: sgpio

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

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