rtacct: 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 CentOS possible default full paths are:

/usr/sbin/rtacct - from package: iproute

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/sbin/rtacct - from package: iproute2

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

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