I am using a Sony (sve15118fnb) laptop. Recently I installed windows 10 and decided to dual boot it with Ubuntu. The disk uses MBR partition table, so the maximum number of primary partitions allowed is 4.

The disk partitions before installing Ubuntu, the red boundary indicates what was a logical partition before installing Ubuntu:


This makes 3-primary and 1-logical partition. But while installing Ubuntu, I went with the default (primary) as the partition type for swap and root directories. And after installing Ubuntu, the disk management shows partitions like this after installing Ubuntu


This makes 5-primary!! and 1-logical partition. How is this possible?

PS: While installing Ubuntu, I didn't get any error/warning about the max number of primary partitions allowed. But every time before booting into Ubuntu this message shows up and only shows when booting to Ubuntu and not while booting to Windows:


  • Ubuntu uses a special type of partition called extended partition.Try googling "ubuntu extended partition". Then you will get an idea about it. – john9983 May 29 '16 at 10:37
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    Apart from the red border, I do not see any difference in the partitions above... Did you really install Ubuntu? Where is it? – dadexix86 May 29 '16 at 10:49
  • I took the screenshots after installing Ubuntu. The red boundary shows a logical partition that existed before installing Ubuntu. The two primary partitions inside the red border are where the swap and root directories are present. – harshatech2012 May 29 '16 at 10:54
  • That "clean" message is the output from a file system check done by Ubuntu, so I would not expect to see it in Windows. It is not an error message. IMHO it's kind of a bug though (introduced in 16.04) to display this message every boot, because it causes unnecessary concern for new users. – Organic Marble May 30 '16 at 12:08
  • Ok. Thank you @OrganicMarble. And I was thinking that maybe I didn't install Ubuntu properly, and its an error. Thank you for the explanation. – harshatech2012 May 30 '16 at 15:22

These non-named partitions on Windows 10 device management are created from Linux Ubuntu and not created from Windows because there are the partitions that would not show up in Computer but you will see it on Device Management and you are unable to access these drives, so you might get the partitions beyond the limit.

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