osv VS xous-core

I've been looking at a few.

https://github.com/cloudius-systems/osv

https://ops.city/ (also nanovms) - this is one that I actually got working to at least demo state

I have also found OSv to be interesting.

https://osv.io/

Wow, just now seeing this topic. I work for a cloud company hosted in AWS. We started out, Netflix/Spotify style microservices. We were all on ec2 images generate by packer (and later with AWS Image Factory). When Docker hit, we kicked the tires but never did anything with it beyond using it for running unit tests, and later, infrastructure tests. 5 years ago, during a hackathon, our little group began experimenting with Unikernels, or library operating systems. Interestingly enough, these Unikernels were all stripped down BSD kernels. OSv is FreeBSD based, and Rumprun is NetBSD based. Services running in EC2 on Unikernels would spin up and start sending and receiving traffic before the AWS EC2 healthchecks completed. They are blazing fast! Only problem in 2017, was the tooling. It would have taken too much effort to use Unikernals with our infrastructure. As soon as they start making Unikernels that can run Java bytecode like native code, the fate of containerization will be sealed, IMO. We could get basic JVM webservers running on OSv, but not Cassandra, not Kafka, not yet. OSv now runs on Firecracker, but I have not tried it out, yet. Some links if you are interested: OSv: https://osv.io Rumprun: https://github.com/rumpkernel/rumprun We used this tooling during the Hackathon, but doesn't look like it has been touched in 3 years: https://github.com/solo-io/unik Unikraft Unikernel Dev kit: https://unikraft.org/ And don't forget Firecracker running in Kubernetes https://www.weave.works/oss/firekube/ And of course, being a FreeBSD subreddit, let's not forget FreeBSD on Firecracker https://www.daemonology.net/blog/2022-10-18-FreeBSD-Firecracker.html

Whats the difference to OSv?

https://github.com/cloudius-systems/osv

OSv Unikernel — Optimizing Guest OS to Run Stateless and Serverless Apps in the Cloud — Waldek Kozaczuk [OSv Committer] Unikernels have been demonstrated to deliver excellent performance in terms of throughput and latency, while providing high isolation. However they have also been shown to underperform in some types of workloads when compared to a generic OS like Linux. In this presentation, we demonstrate that certain types of workloads - web servers, microservices, and other stateless and/or serverless apps - can greatly benefit from OSv optimized networking stack and other features. We describe number of experiments where OSv outperforms Linux guest: most notably we note 1.6 throughput (req/s) and 0.6 latency improvement (at p99 percentile) when running nginx and 1.7 throughput (req/s) and 0.6 latency improvement (at p99 percentile) when running simple microservice implemented in Golang. We also show that OSv' small kernel, low boot time and memory consumption allow for very high density when running server-less workloads. The experiment described in this presentation shows we can boot 1,800 OSv microVMs per second on AWS c5n.metal machine with 72 CPUs (25 boots/sec on single CPU) with guest boot time recorded as low as 8.98ms at p50 and 31.49ms at p99 percentile respectively. Lastly we also demonstrate how to automate the build process of the OSv kernel tailored exactly to the specific app and/or VMM so that only the code and symbols needed are part of the kernel and nothing more. OSv is an open source project and can be found at https://github.com/cloudius-systems/osv.

I guess you could have a JVM like that, but not OpenJDK. There is, however, a unikernel that supports running itself and OpenJDK in the same process: http://osv.io/

> Oracle used to offer an installation mode like this

Oracle, and BEA before them, used to offer a JVM which ran on top of a thin custom OS designed only to host the JVM, you could call it a "unikernel". Product was called JRockit Virtual Edition (JRVE), WebLogic Server Virtual Edition (WLS-VE, when used to run WebLogic), earlier BEA called it LiquidVM. The internal name for that thin custom OS was in fact "Bare Metal". Similar in concept to https://github.com/cloudius-systems/osv but completely different implementation

I think one thing which caused a problem for it, is a lot of customers want to deploy various management tools to their VMs (security auditing software, performance monitoring software, etc) and when your VM runs a custom OS that becomes very difficult or impossible. So adopting this product could lead to the pain of having to ask for exceptions to policies requiring those tools and then defending the decision to adopt it against those who use those policies to argue against it. I think this is part of why the product was discontinued.

Nowadays, Oracle offers "bare metal servers" [1] – which are just hypervisor-less servers, same as other cloud vendors do. Or similarly, "Oracle Database Appliance Bare Metal System" [2] – which just means not installing a hypervisor on your Oracle Database Appliance.

So Oracle seems to have a history of using the phrase "bare metal" in both the senses being discussed here.

[1] https://www.oracle.com/cloud/compute/bare-metal.html

[2] https://docs.oracle.com/en/engineered-systems/oracle-databas...

Xous, the OS that runs on the precursor, may be of interest to look at too:

https://github.com/betrusted-io/xous-core

It is written in Rust and is targeted for a RISC-V

In addition to phil-opp and redox, there's the Betrusted project's Xous kernel, which runs on a RISC-V core that runs on an FPGA. There's even an Xous Book.

You might be interested in Precursor and the Betrusted Platform.

https://www.crowdsupply.com/sutajio-kosagi/precursor

They are trying to have an hardware platform that can be inspected and it is based on an FPGA with a RISC-V Softcore.

Its by Bunnie, and he great talks about the choices and why he made them:

Keynote: Precursor - Trustable Open Hardware for Everyday Use - Bunnie Huang (https://www.youtube.com/watch?v=Fw5FEuGRrLE)

They are also doing their own Rust Message passing OS called Xous that might be of interest.

https://github.com/betrusted-io/xous-core

As for privacy and safety of people, https://github.com/betrusted-io/xous-core/issues/57 way past 1.0. Imagine that. Heh.

There are more good efforts, the BeTrusted guys are working on Xous, its a microkernel for a phone like device called the Precurser.

https://github.com/betrusted-io/xous-core

As a embedded service processor OS for a big server rack, Oxide Computer is working on 'HubrisOS'. They seem to have not released it yet, but that will be open sourced.

https://github.com/oxidecomputer

Those are two efforts where I know real resources are going into.