Yellow Bricks

by Duncan Epping

6.5

Where’s the HA enforce VM-Host and Affinity rules option in vSphere 6.5?

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Last week on (VMware internal) Socialcast someone asked where the UI option is in vSphere 6.5 that allows you to enable the ability for vSphere HA to respect VM-Host Affinity and VM-VM Anti Affinity rules. In vSphere 6.0 there is an option in the Rules part of the UI as shown in the screenshot below.

In vSphere 6.5 that option has disappeared completely. The reason for this is because vSphere HA now respects these rules by default, as it appeared this is the behavior customers wanted anyway. Note, that if for whatever reason vSphere HA cannot respect the rule it will restart the VMs (violating the rule) as these are non-mandatory rules it chooses availability over compliance in this situation.

If you would like to disable this behavior and don’t care about these rules during a fail-over you can set either or both advanced settings:

  • das.respectvmvmantiaffinityrules – set to “true” by default, set to “false” if you want to disable it
  • das.respectvmhostsoftaffinityrules – set to “true” by default, set to “false” if you want to disable it

I hope that helps those looking to make changes to this behavior.

VM showing that HA failure response is disabled in 6.5?

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I had a customer asking me today why on each VM it was showing that all HA responses are disabled. This customer is running vSphere 6.5 and below you can see what the UI showed. Note that it still says the VM is Protected, yet none of the protection mechanisms appeared to be enabled

I asked them to show me a screenshot of their HA configuration, and the HA configuration actually had several of these response mechanisms enabled. I checked my vSphere 6.5 lab and it seems I have the same problem and there’s a UI issue on the VM level details for vSphere HA in vSphere 6.5. I verified with engineering, and this is indeed a known issue which has been identified and is fixed in vCenter Server 6.5.0b! KB Article on the topic can be found here, and in the release notes for 6.5.0b it is mentioned that it is fixed.

Intel Optane support for vSAN, first HCI solution to deliver it

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I am in Australia this week for the Sydney and Melbourne VMUG UserCon’s. Had a bunch of meetings yesterday and this morning the news was dropped that Intel Optane support was released for vSAN. The performance claims look great, 2.5x more IOPS and 2.5x less latency. (I don’t know the test specifics yet.) On top of that, Optane typically has a higher endurance rating, meaning that the device can incur a lot more writes, which makes it an ideal device for the vSAN caching layer.

While talking to customers the past couple of days though it was clear to me that performance is one thing, but flexibility of configuration is much more important. With vSAN you have the ability to select any server from the vSphere HCL and pick the components you want as long as they are on the vSAN HCL.  Or you can simply pick a ready node and swap components as needed. As long as the controller remains the same for a ready node you can do that. Either way, you have choice, and now with Optane being certified you can use the latest in flash technology with vSAN!

Oh for those paying attention, the Intel P4800X Optane device isn’t listed on the HCL yet. The database is being updated as we speak, and the device should be included soon!

Running a Witness Appliance on a 2 Node vSAN config with FT

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I have had various people asking, and to me it felt like an obvious answer, but as multiple have asked over the past couple of month I figured I would dedicate a post to it. The question is if it is supported to run the vSAN Witness Appliance for a 2 Node vSAN configuration on the 2 Node vSAN Configuration itself, but then with vSphere SMP-FT enabled on the Witness for extra protection.

The short answer: No, this is not supported.

The slightly longer answer: No, this is not supported. The vSAN Witness needs to run outside of the vSAN cluster it is acting as a witness for. The reason for this is fairly straight forward: Just imagine the vSAN hosts are partitioned and cannot talk to each other, yet both may have access to the Witness as a result of FT doing what it is designed to do. But those are different instances of the same Witness, which potentially can lead to all sorts of strange problems.

Virtually Speaking Podcast – vSAN Customer Use Cases

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As John Nicholson was traveling in and around New Zealand I was asked by Pete if I could co-host the Virtually Speaking Podcast again. It is always entertaining to join, Pete is such a natural when it comes to these things. I euuh, well I do my best to keep up with him :). Below you can find the latest episode on the topic of vSAN Customer Use Cases. It includes a lot of soundbites recorded at VMware World Wide Kick Off / Tech Summit, which is a VMware internal event for all Sales, Pre-Sales and Post-Sales field facing people.

You can of course also subscribe on iTunes!