xc_restore: 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/lib/xen-4.4/bin/xc_restore - from package: xen-utils-4.4

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

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