ckd2cckd: 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/ckd2cckd - from package: hercules

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

On Debian possible default full paths are:

/usr/bin/ckd2cckd - from package: hercules

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

Error in other languages:
ckd2cckd: bevel nie gevind nie
ckd2cckd: comandă negăsită
ckd2cckd: comando não encontrado
ckd2cckd: commande introuvable
ckd2cckd: command not found
ckd2cckd: käsku ei ole
ckd2cckd: không tìm thấy lệnh
ckd2cckd: komanda nerasta
ckd2cckd: Kommando nicht gefunden.
ckd2cckd: kommandot finns inte
ckd2cckd: komut yok
ckd2cckd: nie znaleziono polecenia
ckd2cckd: níor aimsíodh an t-ordú
ckd2cckd: no se encontró la orden
ckd2cckd: no s'ha trobat l'ordre
ckd2cckd: opdracht niet gevonden
ckd2cckd: parancs nem található
ckd2cckd: perintah tidak ditemukan
ckd2cckd: príkaz nenájdený
ckd2cckd: příkaz nenalezen
ckd2cckd: команда не найдена
ckd2cckd: командата не е открита
ckd2cckd: 命令找不到
ckd2cckd: コマンドが見つかりません