Unfortunately I can’t view this VMworld session as I don’t have an account.

Good to know that there’s more coming on this front from both EMC, Cisco and VMware.
Can’t wait to take these new technologies for a testdrive!

I’m of the same mind – that isolated clusters (options 4 and 5) are the best (there are a number of VM HA and DRS conditions as you noted). The other variations are valid of course, but the litmus test for me is:

1) “do you really not care which side the VMs are on (ergo it’s a MAN or you have existing dark fiber), or are you willing to setup very specific, and relatively complex DRS exclusion rules”

2) “are you willing to do the homework on the VM HA primaries” (as you noted)

At VMworld in session SS5240, we covered what worked and was supported today, and we did a technology preview of whats coming in this area.

On the VMware side, there’s a set of DRS and VM HA changes coming that will broaden the use cases; on the Cisco side, a series of technolgies that make the networking constraints looser; and on the EMC side, the ability to have an active-active storage model across long distances (maintaining the “writeable on both sides simultaneously” requirement for these shared datastore use cases – both for NFS and VMFS use cases).

The design target is to enable the action to also not require all the data replicating all the time (optionally) – so the impact only occurs at the point of vmotion.

Stay tuned – lots coming on this front soon!

First of all thank you for your comments.

When I was asked to look into stretched clusters there wasn’t any storage virtualization solution in place at that site and couldn’t introduce new technologies either.

I wanted to share my thoughts about the options I came up with, without using a storage virtualization solution. Also those storage virtualization solutions aren’t in the field of my expertise (yet). So that’s one thing I have to look into, in the near future.

Luckily the beauty of blogging is you guys commenting on my article.

-Arnim

I must disagree to your conclusion regarding stretched clusters!

If you add a storage virtualisation technology like NetApp Metrocluster, Data Core or FalconStore into the picture and also assume you have sufficant network and storage bandwidth available, then you can clearly build very powerful and simple stretched clusters. Of course this will only work if latency between those two sites is acceptable low.

I agree that this is a long list of “must have”, but at least I have some big customers running this sort of setup very successful.

You point of “VMware official Support” is a nice one .

Alexander

P.S.: In this post I only express my personal oppinions and NOT an official comment by VMware.

As far as I understand, you’re talking about active-passive solutions like Continous Data Access or MirrorView in order to mirror storage between datacenters. What about some kind of storage virtualization? Our VMware consultant recommended SAN Symphony from DataCore- a technician from HP recommended another product although I can’t remember what it was. FalconStore?

Anyway: This would be an active-active mirror without the problems you mentioned above. However, this might be more expansive and would probably result in increased traffic between datacenters. Additionally, datacenters shouldn’t be too far apart.

Nevertheless, I think this is an interesting option. Did you have any special reasons not to include this scenario?

cu

Mario

I mentioned that the first requirement is stretched vlans and that we assume that this requirement is in place. So this means for all design scenarios.
I’ll see if I can put it in the graphs.

-Arnim

One thought, it is not clear on some of your diagrams whether or not you use stretched VLAN (combined with stretched VMware cluster), it would be great if you add that info…

Cheers,
Didier