fatnew: 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/fatnew - from package: cernlib-packlib

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

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