arepack: 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/bin/arepack - from package: atool

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

On Debian possible default full paths are:

/usr/bin/arepack - from package: atool

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

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