ibnetdiscover: 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/sbin/ibnetdiscover - from package: infiniband-diags

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

On Debian possible default full paths are:

/usr/sbin/ibnetdiscover - from package: infiniband-diags

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

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