ompi_info: 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 Debian possible default full paths are:

/usr/bin/ompi_info - from package: openmpi-bin

You may install the required package with command apt-get install {package}

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