Connected my old HDD with usb dock to my computer after migrating to SSD. I was dual booting on that HDD now I want to use it as my storage disk. Yet it has 9 partition connected with Windows or Ubuntu. Gparted was able to delete some of them but some are not allowed to turn into unallocated space. There is a key symbol next to those. I can access every disk so it seems healthy but can't format and converge all of them to one partition. Here is how it seems:
PS: I don't want to preserve any data.
Partition Table for my external HDD
sudo umount <mount-point>
, or with right clicking the entries in your partition list.