visualvm: command not found

Have You tried accessing the binary with the full path?

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/visualvm - from package: visualvm

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