api.vgcreate uses a PE size of 1G
Using such a large extend size leads to potentially unused space of just under 1G per devices.
Why was such a large PE size chosen?
#1 Updated by Lars Marowsky-Brée about 1 year ago
I agree, a 1GiB size for extents doesn't make a lot of sense; that it makes reading LVM2 output easier to read when looking at extents is not really a good reason, and I'm not sure how it allows us to create larger LVs? (This limitations no longer applies for LVM2 format vs LVM1, no?)
#4 Updated by Alfredo Deza 9 months ago
There isn't anything different, we believe that the choice of 1GB for LVM extents made it an order of magnitude easier to calculate space available and the possible waste isn't significant enough to change back.
It becomes more of a problem on very small OSDs, but we aren't optimizing for that use case, so I would recommend pre-creating the LVs if using tiny OSDs is what is needed.