High availability on two boxes

[Gijs]

You might want to take a look at http://www.drbd.org/.
It basically does what you suggest. It creates a software raid 1 
partition across a local and networked partition.
Perfect for real-time syncronisation between disks across a network, 
while not having to resort to expensive stuff like SANs and the like.

Regards,

Gijs

Uno Engborg wrote:
> Hi,
> I'm experimenting with a HA setup on two physical boxes.  The idea is 
> to create virtual Xen machines that  automagically do live migration 
> from one physical box to the other in case of e.g. a hardware failure 
> on one of the physial boxes.
>
> My idea is to create a software raid of networked block devices and 
> real disks.  I.e:
>
> Box A:
> Software raid consisting of:
> Physical disk in box A
> Nework block device exported from box B
>
> Box B:
> Software raid consisting of:
> Physical disk in box B
> Network block device exported from box A
>
>
> On top of this I plan t use  GFS2 and a cluster that handles the 
> migration of the virtual machines.
>
> Any comments on this, would this work, or would it result in deadlock? 
> What about quorum disk? I suppose
> I need one? Most setup of these kind of things usually have their 
> storage on a separate
> SAN, but as this is mostly for experimentation and testing purposes, I 
> would hope that I could do without that for now.
>
> What would be the best way to export the network block devices? I'm 
> thinking iSCSI or GNDB?
>
> If this doesn't  look like a good idea, are there any other way to do 
> this.
>
> Regards
> Uno Engborg
>