keyarch: 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/keyarch - from package: dnssec-tools

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

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