lx26-amd64: 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/share/gridengine/bin/lx26-amd64 - from package: gridengine

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

Error in other languages:
lx26-amd64: bevel nie gevind nie
lx26-amd64: comandă negăsită
lx26-amd64: comando não encontrado
lx26-amd64: commande introuvable
lx26-amd64: command not found
lx26-amd64: käsku ei ole
lx26-amd64: không tìm thấy lệnh
lx26-amd64: komanda nerasta
lx26-amd64: Kommando nicht gefunden.
lx26-amd64: kommandot finns inte
lx26-amd64: komut yok
lx26-amd64: nie znaleziono polecenia
lx26-amd64: níor aimsíodh an t-ordú
lx26-amd64: no se encontró la orden
lx26-amd64: no s'ha trobat l'ordre
lx26-amd64: opdracht niet gevonden
lx26-amd64: parancs nem található
lx26-amd64: perintah tidak ditemukan
lx26-amd64: príkaz nenájdený
lx26-amd64: příkaz nenalezen
lx26-amd64: команда не найдена
lx26-amd64: командата не е открита
lx26-amd64: 命令找不到
lx26-amd64: コマンドが見つかりません