I am unable to create an extended partition on my disk in Gparted: the option is greyed out! I resized the primary partition on the disk to leave some unallocated space, and I wanted to make the extended partition there so I could make 3 logical partitions in there, but I can't.

I do not have any other extended partitions on the disk; the only other partition is the primary partition which I do not want to lose data from.

As you can see in this screenshot, the "Extended Partition" option is greyed out and cannot be selected.

Screenshot of the “Create new Partition” dialog

Any help would be appreciated here!

Output of sudo fdisk -l /dev/sdb:

ubuntu@ubuntu:~$ sudo fdisk -l /dev/sdb
Disk /dev/sdb: 114.6 GiB, 123010547712 bytes, 240254976 sectors
Disk model: Ultra Fit       
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x73736572

Device     Boot      Start        End    Sectors   Size Id Type
/dev/sdb1       1920221984 3736432267 1816210284   866G 72 unknown
/dev/sdb2       1936028192 3889681299 1953653108 931.6G 6c unknown
/dev/sdb3                0          0          0     0B  0 Empty
/dev/sdb4         27722122   27722568        447 223.5K  0 Empty

Partition table entries are not in disk order.

(By the way, in this state there is only the 1 partition on the disk which is NTFS)

  • 4
    If I were to guess, I'd say there is no partition table, because the "partition" is named /dev/sdb. What does it show if you enable "View -> Device Information" in the menu?
    – Freddy
    Sep 29, 2019 at 11:19
  • @Freddy - Yeah, device information says Partition Table: None.
    – Daniel M.
    Sep 29, 2019 at 13:45
  • 1
    @DanielMassey If all data looks okay, you could (1) backup everything. (2) Delete the partition and create a new partition table (menu -> Device -> Create Partition Table), create new partitions and (3) restore your backup.
    – Freddy
    Sep 29, 2019 at 13:53
  • 4
    You actually have a file-system on your device /dev/sdb. You do not even have a partition table and therefore cannot have partitions. @Freddy's comment should be the answer.
    – Hermann
    Sep 29, 2019 at 14:02
  • @Freddy - Yep, I've already began the backup and will do it as soon as that is done! Thanks!
    – Daniel M.
    Sep 29, 2019 at 15:02

1 Answer 1


Like @Freddy stated in the comments, it seems there was no partition table at all on this disk. I have resolved this now by creating a partition table on the disk. Thanks for all your help anyway!

  • Solved for me the problem! It appears that if you have installed a live-iso to an ssd (or usb), this is done without a partition table. So in case you want to delete this partition , you have to create the partition table again before adding new partitions Dec 31, 2020 at 9:14

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