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
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.