[DRBD-user] DRBD and KVM for a HA-Cluster ?

Felix Frank ff at mpexnet.de
Fri Jan 7 09:36:53 CET 2011

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

> The risk here, though, is with split-brains.
> Consider this;
> You have two partition on your DRBD; one each for two VMs. In the course
> of normal operation you have one VM running on NodeA and the other VM
> running on NodeB. DRBD Primary/Primary will allow this. Then though, you
> have a split brain.
> At the moment of the split brain, unless you've configured a stonith
> device in DRBD, either side will go off on their own and your VMs will
> continue to run. From this point on, both sides are "more up to date"
> than the other. This is because both are writing to their VM's partition.


Wasn't the intention to have one LV+DRBD per VM?

Doing dual-primary have the nodes work with distinct parts of the same
DRBD doesn't sound like much of a good idea, because of the scenario you

It *is* a good idea to allow dual-primary when using one LV per VM
though, so that live-migration is available, afaik.


More information about the drbd-user mailing list