https://www.redhat.com/archives/dm-devel/2013-June/msg00026....
https://www.varnish-software.com/blog/accelerating-your-hdd-...
https://www.redhat.com/archives/dm-devel/2013-June/msg00026....
https://www.varnish-software.com/blog/accelerating-your-hdd-...