namei: 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/namei - from package: util-linux-ng

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

On Debian possible default full paths are:

/usr/bin/namei - from package: util-linux

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

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