Hello,
related to shared lvm I was able to find from official how-to/documets only this http://www.tldp.org/HOWTO/LVM-HOWTO/sharinglvm1.html
with recommanded procedure. I'm using shared lvm on the top of iscsi device on 2 node and SAN is able to see lsv/vgs as well. So I have
active same volume group on 3 nodes (3rd is SAN) and all changes that I did like create lvs, snaphots, resizing are immediatly reflected to all nodes.
It looks like metadata are periodically read, without any cluster service behind. What is explanation for this behavior?