Went to /, left clicked, clicked on properties and got wrong results (see attached files).
I'm using PCManFM 1.1.2 on arch linux. The mount point is / and the partition is on top of lvm and luks.
The hard disk has 1tb, the partitions 200gb but it also has links to bigger partitions.
The same on /media/data shows correct numbers. The size on disk is probably good too.
/dev/mapper/vgroup-root on / type ext4 (rw,relatime,data=ordered)
/dev/mapper/vgroup-data on /media/data type ext4 (rw,relatime,data=ordered
Showed this to a friend and he told me the same happens to him (see the screenshot with japanese glyphs)
He is using PCManFM 1.1.0 on gentoo without lvm or encryption
Here is his mount: http://pastebin.com/dJ0G52ta