LMDB performance suffers when used on a journaling filesystem. Consequently, LMDB supports using a plain block device, to eliminate all FS overheads. And yes, a

LMDB performance suffers when used on a journaling filesystem. Consequently, LMDB supports using a plain block device, to eliminate all FS overheads. And yes, all of the perf benefits go out the window if you're running on several layers of virtualization anyway.