xentrace: 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/xentrace - from package: xen-utils-4.4
/usr/sbin/xentrace - from package: xen-utils-common

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

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