By using Solaris / re-implementig KVM on different arch / platform, ofc it's the wrong approach, on one side you what 100s eng at Joyent working on that, where the rest of the world uses native KVM, x86, Linux ect ... it's just not possible on a tech level to compete.
SmartOS beats GNU/Linux feature for feature and it has features like fault management architecture that are science fiction for Linux. For example, it will migrate affected memory pages from portions of the chip with too many parity errors and it will off-line the chip if necessary, but the server will continue to function. All of that will be uniformly reported on top of that and is visible with fmadm faulty. I can off-line faulty processors and replace them on hardware which supports that while the system continues to serve.
Then there is COMSTAR, a reference fiberchannel and iSCSI implementation. illumos inherited the reference NFS V3 and V4 implementations from Solaris. The runtime linker is so advanced in respect to versioned interfaces that it looks like it's magical. The list could go on and on and on... Linux is nowhere near any of that. Linux barely works somehow but when it comes to running serious infrastructure and data integrity, that's not enough. Just because most people think bash completion and GNU commands are what makes GNU/Linux superior doesn't mean that it actually is: it's very crude and unreliable underneath, especially since you have armies of people constantly hacking on it and breaking kernel interfaces, especially in networking. Try running a firewall / VPN company with it to see what a nightmare it is. And that's just one instance.
And then there is cloud: nothing that GNU/Linux has comes even remotely close to how simple, secure and fast Solaris zones in SmartOS are. Literally nothing: I can pull an image with imgadm and instantiate a bare metal performance UNIX®️ or GNU/Linux virtual server in under 25 seconds with vmadm. No Kubernetes or Docker or OpenVZ or Terraform can do that, and those are all afterthought bolt-ons, while imgadm and vmadm are core of SmartOS and its reason of existence.
I see multiple problems with that way of thinking, first HW will fail and AWS, Google ect ... showed us that you should not invest in very sophisticated things for those kind of problems.
It feels that you're building something to avoid HW issue but they will happen no mater what so it's better to invest in HA with a mix of standard servers + SW.
And solaris zones... all the modern tooling are built around Linux / Docker / Kubernetes ect ... so why should I use something that no one uses and lagged behind in term of tooling? Solaris zones are doing 1% of what a modern cloud is capable ( like Kubernetes )
Linux is the present and the future if you think with a small company you can change that you are very wrong, by the time SmartOS get something you have Intel, IBM, RH, Google, AWS that all work on Linux that have thousands of people working on many more things, not to mention HW implementation, and that's not even talking about HW integration, pricing, security, support ect ...
