qstart: 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/qstart - from package: torque-client

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

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