xm: 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/xm - from package: xen-utils-common

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

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