isnssetup: 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/sbin/isnssetup - from package: isns-utils

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

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