Quote Originally Posted by jmo
if your trying to run a fully separate "SAN network" and are looking for full redundancy, you should IMO go for (at least) four Ethernet ports for each Xen server - two redundant ports to redundant switches for the SAN network and two redundant ports (again to redundant switches) for the client-side network... plus, optionally, a management port per server (to separate VM traffic from Xen server management traffic).
Yes, I'd love to do it this way. Unfortunately this is to expensive for this project

Quote Originally Posted by jmo
HA means to avoid single points of failure - so if the connection from the Xen servers to the DSSes are only through the "dedicated switch", then that switch is a SPOF.
Unfortunately I seem to have used the budget already.. so we will have to go with the risk of this one switch to fail. Fortunately the SLA we granted to our customer gives us some room for this kind of stuff.

Quote Originally Posted by jmo
Do you plan to run the Xen servers as a "cluster", with every VM runnable on both servers (take.over in case one of the Xen servers fails)?
Yes

Quote Originally Posted by jmo
How important is *access* to the VMs? You might need to provide redundant access paths to your Xen servers (from the client's point of view).
Most important of all, its for some webapps.

Quote Originally Posted by jmo
How do you define "available"? Is it ok to run all VMs on a single node - ie in case that the link from the client net to one of the Xen servers fail? Does your take-over rule set permit handling such an event?
It kinda does, as the failed VM would be restarted on the other node with the same settings (IP Adress etc.)


Would you have a look at this please?


This shows a simplified network diagram.

All boxes are directly connected to the switch. The two DSS servers are also interconnected with 3 cables (Bonding + Heartbeat).
Does this sound right?

There will be some more cables, as each server has an IPMI module and the DSS servers have a dedicated NIC on the Areca RAID controller..

As I see it the SPOF is the switch (as you mentioned). Besides that, does the setup seem okay to you?

Thank you in advance!