[Info-vax] OS design, was: Re: [OT] Wirth style languages, was: Re: Obscure Ada compiler vendors?

[Simon Clubley]

On 2013-04-09, Keith Cayemberg <keith.cayemberg at arcor.de> wrote:
> On Tuesday, April 9, 2013 7:35:54 PM UTC+2, Simon Clubley wrote:
>> On 2013-04-09, David Froble  wrote:
>> 
>> > Of more concern to me is VMS (as far as I know) is more of a monolith, 
>> > with lots of complexity and inter-relationships.  Is this reality?
>> 
>> Yes. There are inter-relationships in VMS which simply do not exist in,
>> say, Linux, even though both are monolithic kernel designs.
>
> IMO that is one of the many myths that have been perpetuated about OpenVMS
> architecture, also by principals that should know better (Wikipedia also has it
> completely wrong). OpenVMS has a "Layered OS Design" as described by Andrew
> Tanenbaum in his "Operating Systems Design and Implementation"(*). Please see
> sections 1.5 Operating System Structure, 1.5.1 Monolithic Systems and 1.5.2
> Layered Systems. This is a definitive organizational improvement over the
> monolithic Linix, DOS and CP/M kernel designs. Even if the layers may be
> tightly integrated and coupled in OpenVMS, it doesn't change the fact that the
> layers exist and do provide for an organizational division of functionality
> useful in building, changing, enhancing and protecting kernel subsystems and
> structures. Examples in which the layered and modular subsystem design of
> OpenVMS was used to introduce extensive functional enhancements include the
> later introduction of SMP, ACLs, Clusters/Distributed Lock Manager, ODS-5, and
> Kernel Threads not conceived in the original OpenVMS OS Architecture.
>

Excellent.

So after reading the above about how VMS is actually more modular than
Linux, it's now inspired me to want to add a ext2 filesystem to VMS
in the same way as you can add filesystems to Linux.

Where can I find the documentation which allows me to do this ?

Thanks,

Simon.

-- 
Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
Microsoft: Bringing you 1980s technology to a 21st century world