OVMS to Unix migration

[Robert J.M. Edis]

G'day Tom

My first question is:  WHY??????

OpenVMS on an Alpha platform has a lower total cost of ownership than AIX,
Solaris or HP/UX.  You need fewer OpenVMS admin people than you do for any
UNIX system.

However, if you are committed to U**X (I am currently working in a HP/UX
environment), I can share some experience. 

1. DCL scripts:  you can replace with a combination of unix shell scripts
and 'smart' Quick screens to handle virtually ALL of what you do now with
DCL.

2. RMS: Most unix environments either come with an ISAM file system or you
can bolt one one from a vendor.  This is less hassle than migrating to a
RDBMS, and cheaper.  An RDBMS does have major advantages over ISAM on a
large system though.

3. Functionality lost: With good design, virtually NO functionality is lost.
If you make use of VMS mailboxes you will have to emulate these with ISAM
files.  PHD changes are a headache as you have to recompile the PDL for even
a minor change.  Logicals and symbols are replaced by environment variables,
not as flexible or powerfull but they do the trick.

4. Compilation:  This depends on your source code control.  Do all your
compiled files have matching source?  How much source fo you have?  Do you
have VMS specific syntax in your source?  Lots of questions.

The PowerHouse team a Detroit Edison went through such a conversion a year
and a half ago.  The watch this list so hopefully Hassan or Pankaj will
respond.

Just my humble opinions of course.

Regards,

Blue


-----Original Message-----
From: Scroggins, Tom
To: powerh-l@lists.swau.edu
Sent: 4/18/00 3:15 PM
Subject: OVMS to Unix migration

We are investigating migrating our current PH application from an OVMS
box to
Unix.  At a recent conference a collegue had several discussions with
people
who had gone through similar migrations.  Does anyone out there have
documentation on steps for migrating?  Several items we need to address:

- We have lots of DCL.  I have to assume that it is better to emulate
than try
to recode everything.
- We use RMS.  All of our data is in RMS files.  How much is lost by
going
with RMS emulators?  What about migrating to an RDB?
- How much other functionality is lost?
- What about recompiling existing PH code?  Painful?  Easy?

Any information would be appreciated.

Thank you,
Tom Scroggins

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
= =
Subscribe: "subscribe powerh-l" in message body to
majordomo@lists.swau.edu
Unsubscribe: "unsubscribe powerh-l" in message to
majordomo@lists.swau.edu
This list is closed, thus to post to the list, you must be a subscriber.
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Subscribe: "subscribe powerh-l" in message body to majordomo@lists.swau.edu
Unsubscribe: "unsubscribe powerh-l" in message to majordomo@lists.swau.edu
This list is closed, thus to post to the list, you must be a subscriber.