qevent: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/qevent - from package: gridengine
/usr/share/gridengine/bin/lx26-amd64/qevent - from package: gridengine
/usr/share/gridengine/bin/lx26-x86/qevent - from package: gridengine

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