New Implementation - Replication / Redundancy questions

[manfriday]

Hi,

I am looking to virtualize about 12-15 physical servers.

I am looking in to purchasing a pair of new 4-cpu quad core servers and a dell MD3000i san box.

There is also a large BlueArc NAS system in another building on site here, which we can utilize, and we have fiber between the buildings so I dont think bandwidth would be an issue.

The ultimate goal is to have failover and redundancy of the server VM's AND user data, so if something goes down failover is transparent to the user.

If I understand VMotion correctly, that's what I need to use in order to achieve a transparent failover ofvirtual servers.

But if I replicate data from my SAN here on site, to the NAS in the other building, would failover from the SAN to the NAS be possible?

If so, is it possible to make it transparent to the user?

If the SAN fails can VMWare be set up to automatically look at the NAS box for the VM's?

I suppose it would be tough to make something like that transparent to the user, since the rug (or data as the case may be) is basically being pulled out from under VMwares feet.

What are you folks doing about storage redundancy/failover?

Also, what sort of options are there for the actual replication of data from a SAN to a NAS? Im kinda new to SAN/NAS stuff.. I have always used attached storage in the past, so if these are stupid questions I do appologize.

Thanks very much for any direction you can offer.

[Texiwill]

Hello,

If I understand VMotion correctly, that's what I need to use in order to achieve a transparent failover ofvirtual servers.

vMotion is used to move systems from one VI3 host to another. In the case when a host goes down for some reason, VMware HA will failover the virtual servers not vMotion.

But if I replicate data from my SAN here on site, to the NAS in the other building, would failover from the SAN to the NAS be possible?

Not automatically, as VMware HA requires all systems to be using the same shared storage. This can be done with some judicious scripting. The replicated LUN would have to be presented properly and then the VMs started.

If so, is it possible to make it transparent to the user?

VMware HA is the tool that does this and it would not fire unless the VMs were on the same storage. But you can script this to make it transparent.

If the SAN fails can VMWare be set up to automatically look at the NAS box for the VM's?

Only with judicious scripting has this been possible. But in general no.

I suppose it would be tough to make something like that transparent to the user, since the rug (or data as the case may be) is basically being pulled out from under VMwares feet.

Exactly. You would need to at least through the 'switch' that would start up the VMs remotely. There is nothing that is currently automated outside of what people have done for their specific environment.

What are you folks doing about storage redundancy/failover?

Multiple storage processors, multiple fibre switches, multiple fibre cards in essence lots of redundancy on the fibre network.

Also, what sort of options are there for the actual replication of data from a SAN to a NAS? Im kinda new to SAN/NAS stuff.. I have always used attached storage in the past, so if these are stupid questions I do appologize.

VMware is working on a product but vReplicator from Vizioncore can do this now.

Best regards,

Edward L. Haletky

VMware Communities User Moderator

====

Author of the book 'VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers', Copyright 2008 Pearson Education. As well as the Virtualization Wiki at http://www.astroarch.com/wiki/index.php/Virtualization

[mcowger]

Edwards's answer here is dead on.

--Matt

[manfriday]

Thanks very much for taking the time to answer my questions. The answers were very helpful.