ekg2: 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/bin/ekg2 - from package: ekg2-core

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

Error in other languages:
ekg2: bevel nie gevind nie
ekg2: comandă negăsită
ekg2: comando não encontrado
ekg2: commande introuvable
ekg2: command not found
ekg2: käsku ei ole
ekg2: không tìm thấy lệnh
ekg2: komanda nerasta
ekg2: Kommando nicht gefunden.
ekg2: kommandot finns inte
ekg2: komut yok
ekg2: nie znaleziono polecenia
ekg2: níor aimsíodh an t-ordú
ekg2: no se encontró la orden
ekg2: no s'ha trobat l'ordre
ekg2: opdracht niet gevonden
ekg2: parancs nem található
ekg2: perintah tidak ditemukan
ekg2: príkaz nenájdený
ekg2: příkaz nenalezen
ekg2: команда не найдена
ekg2: командата не е открита
ekg2: 命令找不到
ekg2: コマンドが見つかりません