nfacct: 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/sbin/nfacct - from package: nfacct

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

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