ivtscd: 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/ivtscd - from package: nut

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

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