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Does VxRail Stretched Cluster require the vCenter to be located at the witness site?
I am working through the RPQ process for a VxRail Stretched Cluster implementation, and one thing I am seeing in the RPQ Excel document states the following:
"VxRail stretched cluster only support external vCenter and it needs to be deployed on a separate host on the 3rd site. VCSA version is recommended."
I understand the requirement for an external vCenter, but is it strictly required to have the vCenter located at the third, witness site? A better design in my opinion is to have the vCenter configured with vCenter HA (VCHA), with the active node at the "preferred" data site and the "peer" node at the "secondary" data site, with the vCenter witness node at the third witness site. This way vCenter is highly available and located at the two most resilient sites, compared with being in a non-HA configuration at the witness site. Is this a supported design for the external vCenter? Or must it be located at the witness site only?
emc_troy
142 Posts
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May 23rd, 2018 09:00
Bill,
As soon as you vCenter HA is robust enough, the vCenter can be hosted anywhere. We prefer it to be in the third site, but it is up to you.
boyler05
143 Posts
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May 23rd, 2018 08:00
Bill,
What about the case where the customer has an external SAN (i.e. Dell EMC Unity or similar) at the Preferred Data Site for hosting vCenter (i.e. a "Management Cluster")? Any reason why the customer-supplied vCenter cannot be hosted there? I don't see a particular reason why the vCenter would be forced to be located at the Witness site. Typically the hardware, bandwidth, etc. at the Witness site is the worst of the 3 sites, so why would you want your vCenter hosted there? So to be specific: Does Dell EMC support having the customer-supplied vCenter Server running on a non-VxRail hardware stack (servers/SAN) located at the Preferred Data Site?
Thanks,
Bill
Bill_Leslie
56 Posts
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May 23rd, 2018 08:00
It doesn't say it because vCenter just cannot run (be hosted) on the VxRail cluster participating in the Stretched Cluster relationship.
Bill_Leslie
56 Posts
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May 23rd, 2018 08:00
Please refer to this guide: https://www.dellemc.com/resources/en-us/asset/white-papers/products/converged-infrastructure/h15275-vxrail-planning-guid…
vCenter does not need to be located at the witness site.
(Note: The topology you requested is not supported, but is under evaluation by the VxRail engineering team.If it becomes supported the doc at link above will be updated with the appropriate details.)
boyler05
143 Posts
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May 23rd, 2018 08:00
Hi Bill,
I've read through that document several times, and no where does it state that the customer-supplied vCenter must physically run on the witness host. Where are you seeing this?
Thanks,
Bill
boyler05
143 Posts
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May 23rd, 2018 10:00
Thanks for the clarification, Troy. Can you work internally to get the RPQ language updated accordingly? Thanks again for clarifying that locating the vCenter at the Witness site is not a "hard" requirement.
reiberbello
4 Posts
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July 12th, 2018 07:00
Hi,
Starting with VxRail 4.5.200, either a VxRail or a Customer Supplied vCenter Server can be used for stretched clusters. Prior to VxRail 4.5.200, only a Customer Supplied vCenter can be used for stretched clusters. (Note: An RPQ is required for using the VxRail vCenter.)