[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-users] XCP and Openfiler as the storage

On Apr 7, 2011, at 5:22 AM, Rudi Ahlers wrote:

On Wed, Apr 6, 2011 at 7:12 PM, Eduardo Bragatto <eduardo@xxxxxxxxxxxx> wrote:

Openfiler has HA support built in. It uses DRDB and Heartbeat to handle
replication and fail over. If you have two Openfiler boxes, you can
configure them as a cluster right from their web interface -- it seems very
simple, but this is not the Openfiler mailing list, so let's not loose focus
Best regards,

Yes, I know it's not an OF mailing list, but I'm interested in this
kind of setup using something cheap like OF or FreeNAS

Sorry if I was unclear on what I meant.

DRBD® refers to block devices designed as a building block to form high availability (HA) clusters. This is done by mirroring a whole block device via an assigned network. DRBD can be understood as network based raid-1.

Heartbeat is a daemon that provides cluster infrastructure (communication and membership) services to its clients. This allows clients to know about the presence (or disappearance!) of peer processes on other machines and to easily exchange messages with them.

In order to be useful to users, the Heartbeat daemon needs to be combined with a cluster resource manager (CRM) which has the task of starting and stopping the services (IP addresses, web servers, etc.) that cluster will make highly available. Pacemaker is the preferred cluster resource manager for clusters based on Heartbeat. 

Basically DRDB works by replicating everything you write to your disks, via network, to another storage box.

Heartbeat runs on both OF boxes and it keeps monitoring for their presence. If one of the storage servers goes down, the other one will pick up the IP used by the box that just "disappeared" so your clients can still reach the storage server on the same IP with the same data they had on the failed storage server.

This is all handled by OF itself, you only need to do setup two OF boxes in HA cluster via it's web interface.

Best regards,

Eduardo Bragatto.

Xen-users mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.