One of the talks here at LISA13 was one about a new Cloud-optimized operating system called OSv. This is a new thing, and I hadn't heard of it before. Why do we need yet another OS? And one that doesn't even run a Linux kernel? I was frowning through the talk until I got to this slide:
That's the point when I said:
Holy shit! They've built a 64-bit NetWare!
- Cooperative multi-tasking? Check!
- A shared memory space? Check!
- Everything runs in Ring 0? Check!
There were a few other things that made the parallel even more clear to me, but this is a stunning display of evil genius. Even though Novell tried for ten years to promote NetWare as a perfectly legitimate general purpose server for application serving, it never really took off. There were several reasons for this (not exhaustive):
- It was a pain to develop for. The NLM model never got anything approaching wide-spread adoption so you had to get everything just right.
- The shared memory space meant that the OS allowed you to stomp all over other processes running on the system, something that other OSs (Windows, Linux) don't allow.
- If something did manage to wiggle out of the app and into the kernel, it had free reign (though in practice all it did was abend the server; writing exploits is subject to the first bullet-point problem).
- It didn't have any concept of forking, just threads. Which changed the multi-processing paradigm from what it was on most other platforms and made porting software to it a pain.
- There were no significant user-space utilities (grep/sed/awk/bash), though they did get some of that well after they'd lost the battle.
All of these made NetWare a challenging platform to develop for, and challenging platforms don't get developed for. Novell tried to further encourage people to develop for it by getting the Java JVM ported to NetWare so people could run Java apps on it. Few did, though it was quite possible; search for "netstorage" on this blog to get one such application that saw a lot of use.
Have I mentioned that OSv's first release ships with a JVM on it?
The Evil Genius part is that they're not wrong, things really do run faster when you write a kernel like that and run things in the same memory space as the kernel. I got pretty nice scaling with Apache when I was running it on NetWare.
The Evil Genius part is that they're designing this system to be a single-app system, not a general purpose system like NetWare was supposed to be. It runs a JVM, and that's it. The JVM can only stomp on itself and the kernel, and apps can stomp on each other within the limits of the JVM.
The Evil Genius part is that if it does fall over, it's designed to be flushed and a fresh copy spun up in its place. Disposable servers! NetWare servers of old were bastion hosts that Shall Never Go Down. OSv? Not the same thing at all.
The Evil Genius part is that they're doing this in an era where a system like this can actually succeed.
The Evil Genius part is that everyone looks at what they're doing and goes, "...uh HUH. Riiiight. LIke that's a good idea." And like evil geniuses of the past will go unrecognized and slink off to some dark corner somewhere to cackle and dream of world domination that will never happen.