xentrace_format: 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_format - from package: xen-utils-4.4
/usr/sbin/xentrace_format - from package: xen-utils-common

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

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