The Boston Diaries

The ongoing saga of a programmer who doesn't live in Boston, nor does he even like Boston, but yet named his weblog/journal “The Boston Diaries.”

Go figure.

Wednesday, February 09, 2000

So where are the fault-tolerant Unix systems of today?

… and by October of 1990 a complete nanokernel was running on the Omron Luna/88K. The current nanokernel contains approximately 20,000 lines of C code and less than 2,000 lines of assembler code….

In addition, the ability to recover all run-time kernel data from checkpointed state means that an interruption of power does not disrupt running programs. Typically, the system loses only the last few seconds of keyboard input. At UNIFORUM '90, Key Logic pulled the plug on our UNIX system on demand. Within 30 seconds of power restoration, the system had resumed processing, complete with all windows and state that had previously been on the display. We are aware of no other UNIX implementation with this feature today….

The paging system is tied to the checkpoint mechanism, and is discussed in the section on checkpointing, below. Persistence extends across system shutdown and power failure. Several IBM 4341 systems ran for more than three years across power failures without a logical interruption of service.

KeyKOS Nanokernel Architecture

Accordingly, KeyKOS also received a B3 security rating, and it's a multitasking, multiuser system. At best, Unix can get a C2, and Windows NT can get that if it's networking is removed. I don't think it's generally available, but one that is based upon KeyKOS, EROS, is available, and GPLed.

Obligatory Picture

[It's the most wonderful time of the year!]

Obligatory Contact Info

Obligatory Feeds

Obligatory Links

Obligatory Miscellaneous

You have my permission to link freely to any entry here. Go ahead, I won't bite. I promise.

The dates are the permanent links to that day's entries (or entry, if there is only one entry). The titles are the permanent links to that entry only. The format for the links are simple: Start with the base link for this site: http://boston.conman.org/, then add the date you are interested in, say 2000/08/01, so that would make the final URL:

http://boston.conman.org/2000/08/01

You can also specify the entire month by leaving off the day portion. You can even select an arbitrary portion of time.

You may also note subtle shading of the links and that's intentional: the “closer” the link is (relative to the page) the “brighter” it appears. It's an experiment in using color shading to denote the distance a link is from here. If you don't notice it, don't worry; it's not all that important.

It is assumed that every brand name, slogan, corporate name, symbol, design element, et cetera mentioned in these pages is a protected and/or trademarked entity, the sole property of its owner(s), and acknowledgement of this status is implied.

Copyright © 1999-2021 by Sean Conner. All Rights Reserved.