PostgreSQL clustering with DRBD

Hi,
I am in the process of setting up a two node cluster.
Can PostgreSQL use DRBD as its storage?
Since the in-memory database would be synchronized with the on-disk
database.
If this would be done with every query, this would greatly impact
performance.
Since the cluster will be multi-master/dual-primary, do I need to have a
separate block device for each PostgreSQL instance or can it use the DRBD
device?
I read mostly about MySQL clustering with DRBD and there the query cache
should be disabled to make sure data is in-sync.
To me it seems something similar would apply to PostgreSQL.
I believe cybercluster is the most active and complete PostgreSQL clustering
solution.
My endgoal is a two node cluster with load sharing and fail over where both
nodes can perform reads and writes.

Are there any additional caeats I need to look into?

Any feedback is greatly appreciated

Thanks in advance,

Serge Fonville