[Info-vax] New filesystem mentioned

[Kerry Main]

> -----Original Message-----
> From: Info-vax <info-vax-bounces at rbnsn.com> On Behalf Of Chris Scheers
> via Info-vax
> Sent: May 16, 2019 3:36 AM
> To: info-vax at rbnsn.com
> Cc: Chris Scheers <chris at applied-synergy.com>
> Subject: Re: [Info-vax] New filesystem mentioned
> 
> Dave Froble wrote:
> > On 5/15/2019 8:34 AM, Simon Clubley wrote:
> >> On 2019-05-14, Grant Taylor <gtaylor at tnetconsulting.net> wrote:
> >>> On 5/14/19 9:36 AM, Dave Froble wrote:
> >>>> Perhaps because no other OS (well, almost all) has a DLM.  At least
> >>>> that I'm aware of.
> >>>
> >>> Linux has a distributed lock manager in kernel for the GFS2 file
system.
> >>>
> >>
> >> For those of you who has never looked at it, reading the libdlm
> >> documentation is very interesting. Here's the dlm_lock() call:
> >>
> >> https://linux.die.net/man/3/dlm_lock
> >>
> >> And no, you are not looking at a VMS documentation page by mistake.
> >> That really is a Linux man page. :-)
> >>
> >> BTW, here's the overview page for libdlm:
> >>
> >> https://linux.die.net/man/3/libdlm
> >>
> >> Simon.
> >>
> >
> > Interesting.  To me, there are too many similar names and such.  Even
> > AST delivery.  That looks like an implementation of some of the VMS
> > DLM on another OS.  It's always good to copy the best.
> >
> > Similar to some etching used on a VAX chip, back in the day.  The
> > Russians copied the chip, including the etching, which said something
> > about "copying the best".  I don't remember the details.  It was good
> > for some laughs at a DECUS symposium.
> >
> > Locking isn't all that hard to design and implement.  John Santos
> > duplicated the RSTS locking for ROSS/V.  He also helped me implement a
> > locking tool way back then.  When I designed my DAS database, the VMS
> > DLM was available, and, it was cluster aware.  Now, that part is
> > really impressive.  Saw no reason to again re-invent a wheel.
> >
> > Now, if I was told that the people implemented that tool on Linux
> > didn't copy from VMS, I'd highly doubt the statement.
> 
> They may not have copied from VMS directly.
> 
> I vaguely remember an announcement a long time back that a company had
> "acquired" the DLM technology that was used in VMS.
> 
> (I quote, because I don't remember the details.  Given, bought, found,
???)
> 
> I think it was Oracle, but I don't remember for sure.
> 
> This may have made its way into Linux.
> 

You are likely thinking about the Windows NT Clustering product that DEC
created. It used an App level  type DLM.

It was by far the better Windows Clustering technology available at that
time, but like so many other better technology that DEC had ..

DEC sold the technology to Microsoft who immediately shelved it.


Regards,

Kerry Main
Kerry dot main at starkgaming dot com