mk_keymap: 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/share/gfxboot/bin/mk_keymap - from package: gfxboot-dev

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

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