I had one more demo to finish and share and that is the vSAN 6.6 stretched cluster demo. I already did a stretched clustering demo when we initially released it, but with the enhanced functionality around local protection I figured I would re-record it. In this demo (~12 minutes) I will show you how to configure vSAN 6.6 with dedupe / compression enabled in a Stretched Cluster configuration. I will also create 3 VM Storage Policies, assign those to VMs and show you that vSAN has place the data across locations. I hope you find it useful.
BC-DR
Where’s the HA enforce VM-Host and Affinity rules option in vSphere 6.5?
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.
VMware vSAN 6.6 demo
I was playing around with a vSAN 6.6 environment yesterday and I figured I would record a quick demo of some of the new functionality introduced. Took me a bit longer than expected, but here it is. I hope you will find it useful, a 1080p version can be viewed on youtube.
VM showing that HA failure response is disabled in 6.5?
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.
HA disabled VMs not registered on other hosts after failure?
A couple of weeks ago one of our SEs asked me about vSphere HA functionality that was introduced a while ago, which is the ability to have HA disabled VMs being registered on other healthy hosts in a cluster after a failure. Not only does this apply to “HA disabled VMs” but also to powered-off VMs. This functionality was introduced to make it easier to power-on a VM after a host failure which was powered off before the failure, or which was disabled for HA restarts. Without this functionality you would need to re-register the VM on a different host, which are various unneeded steps.
The customer testing this scenario had noticed that whenever a failure occurred HA disabled, and powered off, VMs did not get registered. Strange as the documentation states the following:
“If a host fails, vSphere HA attempts to register to an active host the affected virtual machines that were powered on and have a restart priority setting of Disabled, or that were powered off.”
After talking to the vSphere HA engineers it was discovered that there was a bug in vSphere 6.0 U1 and U2. This bug resulted in the fact that HA disabled (or powered-off) VMs were not registered on other hosts. Very annoying. Fortunately, this problem has been solved in vSphere 6.0 U3. If you rely on this functionality to work correctly, please upgrade to vSphere 6.0 U3 to fix your problem. Thanks!