gpart: 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:

/sbin/gpart - from package: gpart

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

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