dphys-config-quota: 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

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/share/doc/dphys-config/examples/site.example/local/sbin/dphys-config-quota - from package: dphys-config

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