dtc_change_bsd_kernel: 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/sbin/dtc_change_bsd_kernel - from package: dtc-xen

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

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