We have announced that with the upcoming DRBD 8.3 release (currently scheduled for the end of this year), all those features that are currently commercially licensed in our DRBD+ add on will be merged into the GPL DRBD main source tree. That means that stacked device support, huge device support (larger than 4TB per device), and checksum-based resync are all coming to DRBD.
DRBD ist ein wichtiger Baustein im Linux HA Stack und mit den Features aus DRBD+ wird es für MySQL/Sun sehr viel einfacher, die DRBD-Entwicklung unter der GPL zu fördern und weiter zu führen.