DSXchange

Out of the two methods of upgrading from DataStage 7.5.2 to Information Server 8.1 on Unix platform.

Basic Method: Where we upgrade the existing 7.5.X version to 8.1 version without uninstalling the 7.5.X

Complete Method: Where we uninstall 7.5.X and then install 8.1 version.

Which one is better over the other.Which one is being used more common.

Could someone give pro's and con's of each method. And outweigh one over the other.

Could you tell in which phase your project is in?

If it is in production already and you have a lots jobs then upgrade is better. If in development phase fresh install wouldn't make any difference.

And one more thing. What exactly is the "X" in 7.5.X?

--Tony

Upgrade from 7 to 8 is generally considered to be less reliable than doing a clean install. There are several threads on DSXchange on this subject already.

antonyraj.deva wrote:What exactly is the "X" in 7.5.X?

Just a placeholder. 7.5.X might represent 7.5.1, 7.5.2 or 7.5.3.

If you are talking about installing on your development box, I'm going to say "neither" of your two methods is my preferred migration path. For the last two years I've been doing upgrades for clients - moving them from pre-8 releases to 8.1 (I won't touch 8.0).

My concerns are:

1) Upgrading in place. Not recommended by anyone. Even IBM refuses to do upgrades in place anymore - they've been burned too many times. It is just too difficult to get a good installation on top of an old installation.

2) Uninstalling 7 and Installing 8 on the same machine. If this is your development box, then you are going to have issues.
- You lose your ability to support production during the migration
- You lose your ability to cross-compare source / output between the two releases (unless you use your production box - something usually not allowed).
- If you forgot to backup something, retrieving it could be exceedingly difficult, especially if you don't have the source for it on the production system.

What I recommend is installing 8 on a separate box if at all possible. If you have a separate QA system I have seen customers modify their procedures to allow them to use the QA system as their new release 8 box during the migration. I've also seen customers use virtual machines temporarily until they have everything ready to swap out. One customer even used a very old semi-retired system to install 8, they just couldn't do performance testing.

One customer who didn't have an extra box decided to wait until they upgraded their hardware, and did it as part of the hardware upgrade - installing 8 on the new box.

asorrell wrote:If you are talking about installing on your development box, I'm going to say "neither" of your two methods is my preferred migration path. For the last two years I've been doing upgrades for clients - moving them from pre-8 releases to 8.1 (I won't touch 8.0).

My concerns are:

1) Upgrading in place. Not recommended by anyone. Even IBM refuses to do upgrades in place anymore - they've been burned too many times. It is just too difficult to get a good installation on top of an old installation.

2) Uninstalling 7 and Installing 8 on the same machine. If this is your development box, then you are going to have issues.
- You lose your ability to support production during the migration
- You lose your ability to cross-compare source / output between the two releases (unless you use your production box - something usually not allowed).
- If you forgot to backup something, retrieving it could be exceedingly difficult, especially if you don't have the source for it on the production system.

What I recommend is installing 8 on a separate box if at all possible. If you have a separate QA system I have seen customers modify their procedures to allow them to use the QA system as their new release 8 box during the migration. I've also seen customers use virtual machines temporarily until they have everything ready to swap out. One customer even used a very old semi-retired system to install 8, they just couldn't do performance testing.

One customer who didn't have an extra box decided to wait until they upgraded their hardware, and did it as part of the hardware upgrade - installing 8 on the new box.

How about this approach,
Using multiple instances of Datastage on same server.

Say on Test Box which has 7.5.2 instance, install new instance of 8.1 (second instance).
And then uninstall DEV 7.5.2 and install 8.1. In the meantime development can be done on Test Box.

Does this looks like good plan.

Technically that would work, as each machine only has one 8.x instance and now the itag can be specified as a non-default one.