Working with multiple InfoSphere Information Server engines on one computer

You can install multiple engines on only Unix or Linux computers. When multiple versions of InfoSphere® DataStage® are installed on a single computer, you must verify that the current environment is set for the version on which you want to perform administrative tasks. You need to follow this procedure before you start, stop, or update an engine.

About this task

You identify the InfoSphere Information Server engine that you want to start or stop by setting the $DSHOME environment variable to reference the DSEngine subdirectory of the server that hosts the engine. For example, there are two engines on the same computer with the following DSEngine subdirectories:

/disk1/Ascential/DataStage/DSEngine (Version 7.5.1 engine)
/opt/IBM/InformationServer/Server/DSEngine (Version 8.7 engine)

Important: When you install the InfoSphere Information Server engine tier on a computer that runs UNIX, the file /.dshome is created. This file contains the path that is used as the default setting for the $DSHOME environment variable. Before and after you install an additional InfoSphere Information Server engine, delete the /.dshome file. When a computer hosts more than one InfoSphere Information Server engine, having a default setting for the $DSHOME environment variable might result in administrative tasks being run on the wrong engine.

If you are going to use the same InfoSphere DataStage administrator ID for more than one engine on the same computer, you should not source the dsenv file in its profile. Avoid mixing the InfoSphere DataStage environment settings before running administrative tasks.

Procedure

Log on to an operating system terminal as the InfoSphere DataStage Administrator.
Source the dsenv file.
1. Set the $DSHOME environment variable to point to the /opt/IBM/InformationServer/Server/DSENGINE directory. Alternatively, you can set and export the DSHOME value in the dsenv file.
2. Change to the directory that contains the dsenv file, which you specified /opt/IBM/InformationServer/Server/DSENGINE.
3. Run the following command to source the dsenv file.
```
. ./dsenv
```

What to do next

After the environment is set to the proper version, you can administer the engine. For example:

Enter the following command to stop the engine services:
```
$DSHOME/bin/uv -admin -stop
```
Wait 30 seconds so that the engine services stop.
Enter the following command to start the engine services:
```
$DSHOME/bin/uv -admin -start
```

Apply updates for the current version that you are working on.