What are vSAN Nested Fault Domains. For vSAN OSA and vSAN ESA. The Complete Guide

So you have heard of VMware vSAN Nested Fault Domains, but not sure what they are or how to set them up. We will cover Nested Fault Domain in great detail in this video for both the Original Storage Architecture (OSA) and the newer vSAN Express Storage Architecture (ESA).
Complete lecture with demo's at the end.
Enjoy and Leave comments below..

[@deepazure-cr8le]

Hi, Steve,
Thanks a lot for the amazing content I've ever seen anywhere .
Here is something I wanna ask
26:08->SiteMirror-FTT=1(ESA) This storage policy was created
26:46->Site Mirror- Raid1[selected ] But this policy was selected .
28:31->
T1 disk on esxi-04 has only 3 component , why ? it is not like any disk on esxi-05
Either it should be 4 component (3 RAID O child_component +Performance leg component ) or only 1 Performance leg component .
I fliped back all previous video for vSAN, but did not find when policy "Site Mirror- Raid1" was created,
probably it was created in your other lab or whatsoever.
Would you please re-select the expected storage policy"SiteMirror-FTT=1(ESA)" to see if everything is expected , thanks again

[@TechUnGlued]

Thanks for watching.. Very interesting. Not sure if I trust the GUI to report these things. I think there is a bug. For example, notice there is a witness on host 5. It did not show that in the previous screen.. I can not verify it now, as my lab has been re-imaged for my VCF Series..I going to do another video on this topic with the stretch cluster and the components.. Thanks again and have a good one.

[@tonyhall699]

Thanks, but I found this a little complicated so can I summarise. For OSA and ESA, vSAN "nested" Fault Domains means 2 levels of failure, the first level is within a site, i.e., only one of the following can fail: one disk, one server, or the network connection. The second level of failure means either the Primary or Secondary site can fail. vSAN "nested" Fault Domains only apply to 2-node clusters running FTT=1, FTT=2 or RAID 5 Erasure Coding only because there is a limit of 5 Disk Groups in 2-Node Clusters.

[@TechUnGlued]

You pretty much got it. Remember it also applies to Stretched clusters.. I have a video coming out soon on Adaptive Quorum, which you will want to watch.. Have a good one