qdisable: 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/qdisable - from package: torque-client

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

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