lttng: 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 CentOS possible default full paths are:

/usr/bin/lttng - from package: lttng-tools

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/lttng - from package: lttng-tools

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

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