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

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

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