Does LVM support unwritten extents? I want to tune samba on a system that has LVM2 under it. I have started to read an article which made me to ask this question, if my partition supports unwritten extents or not, I couldn't find it by googling it.

As Stéphane Chazelas said, LVM is irrelevant.

You can see what type of partition table you use for example by `mount`.

I have ext4 on top of my LVM, but adding to my samba config the `strict allocate = Yes` did stop my samba working, being accessible.