See: http://msdn.microsoft.com/en-us/library/bb525577%28VS.85%29.aspx

It’s worth noting that VMware/ESX presents itself identically to all editions of W2008 and is not aware of which version of the OS is running on it. As such, any issues such as this where different behaviour is experienced on different editions is always going to be due to the differences in the OS. As Stu mentioned, the code *base* is the same between editions, but the actual running code / settings (obviously) isn’t.

VMware will be improving the documentation around this issue.

Disclaimer: I work for VMware, know Stu, and have worked on this case.

So I suspect you are indeed right in supposing it has something to do with the way the disks are presented to the guest, which will make this into an “undocumented feature” of Virtual Hardware 7 rather than a bug

I guess it has something to do with how the disks are enumerated or presented to the OS. So this behaviour depends on the (type of) array controller.

You are right regarding the triviality of a workaround (which we have indeed implemented), care to share some more information how you know the codebase is not the same? Remember Microsoft was the first company I contacted about this on the same assumption, they don’t treat calls from us lightly (the same as VMware don’t) and they came back to us saying the codebase is the same. Depending on what VMware come back with, we may need to have a chat with Microsoft again.

I could see how this might be the default behaviour for adding disk to a running machine, but not for a clean install… as I said, we cannot reproduce this on physical, have you been able to?

And thx for the comments

I do agree on the fact that using multiple vmdk’s gives you more flexibliity and whatsoever, heck it’s something I tell my customers as well.

If I read your post correct, you stated the problem only occurs on “Windows Enterprise editions (2008)”. Microsoft told you the install base is the same. Well it’s not.

I encountered this behaviour with “unattended” setups aswell. Even before there was anything like “vSphere hardware” out there. When you installed a Windows 2008 enterprise edition using the “lsilogic”, the second and other disks started offline aswell. You could try asking it at “http://blogs.technet.com/filecab/” perhaps they have an answer.

All I can say is: if you take a windows 2008 enterprise edition and add a second disk to it, it will be offline. It is not a VMware bug and it’s not a microsoft bug. Microsoft intented it to be this way. As an entprise OS CAN be (which doesn’t means it will be) part of a failover cluster, you do not want disks to be online immediately. Hence they probably made the decission for the Enterprise flavour to have additional disks offline.

If you perform a new install of a VM + OS, I can’t see how this is a problem. Or it’s a manual action to put the disks online, or just let it be part of you scripted rollout. Diskpart can take care of this just fine.

However If you do an “virtual hardware” upgrade, then I guess this can be pretty annoying. What happens if you upgrade from hardware version to version 7? Does it actually use the lsi sas controller then? If that’s the case, i’m not surprised this happens.