crda: 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/crda - from package: crda

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

On Debian possible default full paths are:

/sbin/crda - from package: crda

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

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