mkchdr: 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 Debian possible default full paths are:

/usr/bin/mkchdr - from package: snacc

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

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