Migration of whole application from Open VMS to UNIX environment

[princetd]

Since our project demands migration from Open VMS to UNIX and I have been tasked to port an application from open VMS to UNIX. I would like to gather all/any information regarding the tools used for it and also the elegant solution to attain it.
If you know any efficient tool for migration, please provide me with the information and price. It would be highly appreciable if you could suggest me other alternatives to make migration easier. Is it easier to migrate it manually? If no, why isn't it efficient? What are the drawbacks on migrating it manually? Would you be in a position to render us with some other best solutions for migration?
I would greatly appreciate if you could throw some light in to the migration solutions for Open VMS to UNIX.

[Ian Miller.]

is it too late to say NO?
Depends on how much VMS specific code in your application. Ranges from none e.g. all standard fortran-77 just recompile and go to lots of calls to VMS system services and knowlege of VMS internals leading to a re-write.

[Antoniov.]

Unix and VMS are a lot different.
I've evaluate a few month ago migration of my procedure.
Main problem areas are:
1)Command shell are very different; if you use DCL command procedure, you have rewrite without any auto conversion.
2)System call; I've used many SYS$QIO that doen't exist on unix so I should change manually the code.
3)Indexed/Isam files are native on VMS; so you could convert any isam file to seuqential e reconvert on unix in isam based on product you will use.
There are also other (minor) areas as:
a)Filename are case sensitive in unix;
b)Some language characteristics are different (using C or Cobol you could compile in full ANSI to keep compatibility);
c)System security is a few different; in unix delete and write priv are unique and there is not a system group;
d)Interprocess comunication are different; VMS use mailbox device, unix pipe and programs have different response;
e)Application kill work differently;

DEC/Compaq some year ago haved a posix product to emulate and develop unix application on VMS; now AFAIK is not yet avaiable.

Also you can see:
http://h71000.www7.hp.com/wizard/student_research.html
ftp://ftp.digital.com/pub/Digital/dec-faq/vms
http://h71000.www7.hp.com/portability/index.html
http://h71000.www7.hp.com/portability/gnv.html
http://h71000.www7.hp.com/portability/72.html

Also you can search using "unix portability" on vms home page
http://h71000.www7.hp.com/index.html

H.T.H.
Antoniov

[Moderator edit: The above links are no longer valid. Please refer to https://support.hpe.com/]

[Ian Miller.]

the references to unix portability on the VMS web site are about porting FROM unix TO VMS (which is the sensible direction :-)

[Antoniov.]

Yes Ian,
but a lot of problems are bidirectional, so it's possible evaluate the some difficult to meet.
A project of portability is very complex and every information may be usefull.

Bye
Antoniov

[Martin P.J. Zinser]

Since you seem to be looking for services have a look at

http://www.accelr8.com/migprod.html

Disclaimer: I do have no experience with them. I do not recommend migrating to Unix and we do not have plans to do it ;-)

[princetd]

Dear Sir

At the outset, I would like to thank you for the overwhelming responses, which I received through this forum. And now I have a better understanding on the difficulties and pre-requisitions needed for the migration.

Since our client has already taken a decision and we put reasonable amount of effort on the migration, we are not in a position to step back or re-evaluation of the same.

As our project is in the critical phase of requirement gathering, it may not be advisable to think about the difficulties of migration. I would like to focus on the tool, which can give us a most elegant and efficient way of migrating my whole application from open VMS to UNIX.

Please provide me with more information on the points given below:

1) Tool information
Which is the best tool?
Answer:

Does the tool take care of all the issues in migration?
Answer:

What are the drawbacks and advantages of the tool?
Answer:

2) Manual migration
Is it easier to migrate it manually? If no, why isn't it efficient?
Answer:

How we can go about it?
Answer:

What are the drawbacks and advantages of doing it manually?
Answer:


3) Education on Migration
Is there any book available in the market? Who is the author of the book?
Answer:

Are there any tutorials available?
Answer:


4) Comparison study

Could you please provide me with comparison study on different tools?
Answer:

5) Comparison study on manual migration
Which is the best solution out of manual and migration using tool?
Answer:
Please provide the reasons for not choosing it as a best solution?
Answer:

Once again I express my gratitude for taking out your valuable time for solving my problem.

[Ian Miller.]

I think you will need to pay for consultancy for this. The sort of detailed answers you want require significant work and that costs :-(

[Martin P.J. Zinser]

I do agree with Ian. Without a detailed study of the application involved it would be irresponsible to make recommendations in this area.

Another professional company offersing such services is Sector 7

http://www.sector7.com/products-and-services.htm

And yes I still recommend first to define your problem clearly and investigate if it can be resolved by other means than a migration, since such endeavours tend to be costly and time consuming at best for non trivial cases.

[Mike Naime]

Sucks to be you I guess. :-) It sounds like you have been dumped on with the migration of an application that you know nothing about, and do not have any clue as to how to go about it!

I gotta agree with Ian and Martin, without your specifying what you are trying to port, it is impossible to make any recomendations. We know the VMS side, but what UNIX Hardware/OS flavor are you talking about? IBM AIX? HP UX?, SUN? Compaq/HP True64? Linux? The hardware that you are migrating to makes a HUGE difference in the portability.

Also, experience says that answering any of the questions that you are asking in your second post is usually done by a company that charges for these same services. Something that you are trying to do in-house it seems.

You could look to see if there is a similar Application running on a Unix platform that could potentially service the application needs of the client.

Do you have to transfer old data as well? IF you can find a similar application, potentially you would only have to transfer the actual data between the two platforms.

Good Luck!