pvrenderserver_openmpi: 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/lib64/openmpi/bin/pvrenderserver_openmpi - from package: paraview-openmpi

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