Maximum cluster is eight ESX hosts?

[RobSF]

I just built a demo View in our test lab, and everyone thinks it's the coolest thing they've ever seen. So far, so good. Now I need to move into production very rapidly, and I have a concern. In a few months, we are moving to a new datacenter. Because of the increased demand for VMs, we are planning to build the new VI 3.5 cluster with nine hosts. But the View documentation all claims that the maximum cluster size is eight hosts. Why?

Normally, I'd trust the documentation. But this limit just seems bizarre to me, so I'll ask: Can I really only have eight ESX hosts in a cluster that runs View? Is there any way around this limit? I know that I can simply make multiple clusters, but I'd really like to avoid doing that.

[admin · Accepted solution]

That's correct. There is a limitation of 8 hosts per cluster due to a VMFS restriction.

Blog:

http://communities.vmware.com/blogs/dommermuth |

[RobSF]

Well, shoot. Time to re-design our VI into two clusters. Any idea if this limitation will be fixed in a new version?

Thanks for the speedy answer!

[lbourque]

This only applies if you are doing Composer (Linked Clones). If you are doing vCenter provisioned machines (i.e., from Templates) then you can have up to 32 in a cluster.

The limitation is due to Composer (you'll find a similar limitation for Lab Manager) and as Christoph points out it's due to a VMFS limitation with linked clones. It is a hard limit (any cluster larger than 8 will not show up as a choice for linked clones).

[admin]

Right, I thought he was talking about LC.

Blog:

http://communities.vmware.com/blogs/dommermuth |

[RobSF]

I was talking about Linked Clones. I didn't mention Linked Clones in my question, but you helpfully read my mind.

So, on the follow-up question: Any ideas about when this limitation might be overcome? Does vSphere 4 have a newer version of VMFS that doesn't have the same issue?

[aj205]

The VMFS limitation will still exist in vSphere.

[Steven_Rodenbur]

"That's correct. There is a limitation of 8 hosts per cluster due to a VMFS restriction"

But when using NFS, the whole concept of VMFS is not used at all so why not lift the limitation in such an environment.