r2test: 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/r2test - from package: libopenr2-bin

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

Error in other languages:
r2test: bevel nie gevind nie
r2test: comandă negăsită
r2test: comando não encontrado
r2test: commande introuvable
r2test: command not found
r2test: käsku ei ole
r2test: không tìm thấy lệnh
r2test: komanda nerasta
r2test: Kommando nicht gefunden.
r2test: kommandot finns inte
r2test: komut yok
r2test: nie znaleziono polecenia
r2test: níor aimsíodh an t-ordú
r2test: no se encontró la orden
r2test: no s'ha trobat l'ordre
r2test: opdracht niet gevonden
r2test: parancs nem található
r2test: perintah tidak ditemukan
r2test: príkaz nenájdený
r2test: příkaz nenalezen
r2test: команда не найдена
r2test: командата не е открита
r2test: 命令找不到
r2test: コマンドが見つかりません