Re: Help in DSM design

[Kragen Sitaker]

Horst von Brand quoted Paul Jakma as saying:
>   > correct me if i'm wrong, but aren't all the SysVR4 derived unices
>   > (T64/IRIX/Solaris/Unixware) using Mach based kernels? And MacOS X too?
>
>   All monolytic, except possibly MacOS X (don't know that one, and I
>   remember
>   Apple's Linux was on Mach, because they wanted to build their OS based on
>   Mach, so it could be). WinNT was based on Mach, but is going to monolytic
>   step by step too. The OS of the huge multiprocessor CRAYs was a
>   microkernel
>   OS running on what was essentially a cluster of machines with a very fast
>   internal network, dunno what became of that.

I didn't know NT was Mach-based --- that's very interesting.

I chatted with Wilfredo Sanchez about this a few weeks ago.  I thought
I understood him to say MacOS X was based on Mach, but the BSD services
were integrated into the kernel, not running as a server atop it.

On the plus side, QNX is also microkernel-based, and it's quite
successful in its niche --- although, of course, it won't be able to
compete with free software in the long run.  Likewise for AmigaDOS.

I don't know of any other successful microkernel OSes.  But then, I
don't know of that many successful OSes at all.  Typically one OS
dominates a platform until the hardware becomes obsolete.

-- 
<[e-mail]>       Kragen Sitaker     <http://www.pobox.com/~kragen/>
The Internet stock bubble didn't burst on 1999-11-08.  Hurrah!
<URL:http://www.pobox.com/~kragen/bubble.html>
The power didn't go out on 2000-01-01 either.  :)