I want to create HA cluster with 2 nodes. First node is physical machine, second is virtual (under ProxMox). Both running under Ubuntu. I know how to make HA with corosync and pacemaker. How i can make replication/mirroring of partitions? Is it possible without using NAS storage?
Yes, that's perfectly possible using SAN technology instead of NAS. Question answered ! Applause!
As the above is very probably not what you wanted to hear as SAN is more expensive than NAS, you can also do that using DRBD however it's going to be a highly customized system that no one else except you is going to be able to maintain. The logical solution is SAN or if you can't afford SAN, use NAS.