mountavfs: 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/mountavfs - from package: avfs

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

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