formatting external harddisk

[Philippe Landau]

>>>>> found no GUI formatting tool (is there one ?)
>>>> GParted
>>> i installed it now, switched to sda,
>>> created a disk label (default: dos),
>>> clicked on "unallocated", new partition, fat32,
>>> apply but get "Error while creating /dev/sda1"
>> You have to make sure it's unmounted when trying to format a drive
>> with gparted.
> how can i unmount it ?

after successfully formatting it yesterday,
today after reboot it gets mounted automatically,
but shows only 1022 MB free space of the 190 GB.
now when i look at it in gparted again,
i see 1022 MB unused, 189'758 MB used, fat32.
now i know gparted is not supported in Ubuntu.

does Ubuntu offer a way to format an external harddisk
and transition data from Mac OS X to Linux ?

kind regards     philippe