As some of you already know it, DRBD is now (since kernel 2.6.33) part of the mainline/upstream kernel. Some were expecting RHEL6 to come with that kernel (used for Fedora 13). The latest RHEL6beta2 still comes with 2.6.32, which doesn't include DRBD support. Of course we still don't know what the 'frozen' RHEL6 kernel will be but on the other hand, we know that Red Hat quite often 'backports' modules from newer kernel into the RHEL kernel. What about DRBD ? At the time of writing this blog post, it seems still undecided, but you can follow the DRBD RFE on Upstream Bugzillato get a clue, or even comment on it if you have a bugzilla account to  make hear your voice. On the other hand, you can still be sure that even if DRBD isn't part of EL6, CentOS will still ship it in the Extras repository, like for EL4/EL5 ...