I wanted to convert stand alone mongodb to replica, so I followed this tutorial https://docs.mongodb.com/manual/tutorial/backup-with-filesystem-snapshots/. I got this problem:

Using default stripesize 64.00 KiB.
Volume group "vg0" not found
Cannot process volume group vg0

when I typed: 

lvcreate --size 100M --snapshot --name mdb-snap01 /dev/vg0/mongodb

What is volume group describe for in there?

Help me, pls!
Thank you so much!