[DRBD-user] DRBD primary/primary for KVM - what is the best option?

Michael Iverson dr.michael.iverson at gmail.com
Mon May 10 17:30:52 CEST 2010

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

I'm just about to embark on my first adventure with DRBD, and I'm
interested in some advice on the most reliable approach.

I'm going to have two servers configured as a DRBD cluster, with
either a gigabit ethernet or infiniband link between them. This
cluster will host a number of virtual machine images, using KVM,
likely using Convirt as a management tool. I will have one or more
machines in addition to the two main machines, which will be used to
host images during maintenance or in the event of a machine failure.

My question is how best to export file system images to the various
machines. My first thought was to use a primary/primary setup and
export LVM volumes via multipath iSCSI. The advantage here is that the
load on the network and file system is spread evenly, the
configuration allows for failover from just about any conceivable
failure, and direct LVM access minimizes the file system overhead. The
configuration seems to be fairly complex, but I've tackled similar
complexity in the past without concern.

However, In my research, I've come across articles like this: This is causing me to second guess as
to whether this is the best approach to take. I'm struggling to find
consensus on the web as to the best path to take.
Obviously, I have other options at my disposal, including:

1. Add OCFS2 to the mix, and use file-based images instead of LVM volumes.
2. Abandon iSCSI for NFS.
3. Abandon multipath in favor of a simple heartbeat failover.
4. Switch to a primary/secondary configuration.

Does anyone have opinions on the most appropriate path to take?

Dr. Michael Iverson
Director of Information Technology
Hatteras Printing

More information about the drbd-user mailing list