Ubuntu 18:04 LTS

Folks, system working fine but for some reason I have four folders that appear when started showing contents of different partitions.

None of the folders appear in fstab or mtab so I am not sure where they are being produced from.

From my file manager I get the following;

/dev/dm-1
/dev/dm-2
/dev/sda3
/dev/sda6
It is a tri-boot system with Ubuntu my main system on /dev/sda5
Windows10 on /dev/sda3
Fedora on a LVM system on /dev/sda7 (Think that is dm-1 and dm-2)

/dev/sda6 I am not sure of, it contains boot and efi files but my efi partition is actually /dev/sda1

My question really is; where might these folders be being created?

Geoff