Choosing a primary installation
On systems that support multiple installations of IBM® MQ ( UNIX, Linux®, and Windows ), the primary installation is the one to which IBM MQ system-wide locations refer. Having a primary installation is optional, but convenient.
Before IBM WebSphere® MQ 7.1, only one instance of the product could be installed at any time. On Windows systems, several global environment variables were set to point to that installation. On UNIX and Linux systems, symbolic links were added to /usr/lib, /usr/bin, and /usr/include, also pointing at that single installation.
From Version 7.1, you can install multiple versions of IBM MQ on UNIX, Linux, and Windows. It is possible to have more than one installation of IBM MQ on one of these systems at any time and, optionally, to configure one of these installations as the primary installation. Environment variables and symbolic links pointing to a single installation are less meaningful when multiple versions exist. However, some functions require these system-wide locations to work. For example, custom user scripts for administering IBM MQ, and third party products. These functions work only on the primary installation.
On UNIX and Linux systems, if you set an installation as the primary installation, symbolic links to the external libraries and control commands of that installation are added into /usr/lib, and /usr/bin. If you do not have a primary installation, the symbolic links are not created. For a list of the symbolic links that are made to the primary installation, see External library and control command links to primary installation on UNIX and Linux.
On Windows systems, the global environmental variables point to the directories into which the primary installation was installed. These environment variables are used to locate IBM MQ libraries, control commands, and header files. Additionally, on Windows systems, some features of the operating system require the central registration of interface libraries that are then loaded into a single process. With multiple versions of IBM MQ, there would be conflicting sets of IBM MQ libraries. The features would try to load these conflicting sets of libraries into a single process. Therefore, such features can be used only with the primary installation. For details about some of the features that are limited to use with the primary installation, see Features that can be used only with the primary installation on Windows.
| Options | Valid installation configurations | More information | |
|---|---|---|---|
| Primary | Non-primary | ||
| Single installation of Version 7.1, or later. | Version 7.1, or later. | None | If you want to continue working with a single installation in the same way as previous releases, configure your installation as the primary installation. For information about this option, see Single installation of IBM WebSphere MQ 7.1, or later, configured as the primary installation |
| None | Version 7.1, or later. | If you want to continue working with a single installation, but do not want symbolic links or global environment variables created for you, configure your installation as non-primary. For information about the implications of this option, see Single installation of IBM WebSphere MQ 7.1, or later, configured as non-primary | |
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Multiple installations: Version 7.0.1 and Version 7.1, or later. |
Version 7.0.1 | Version 7.1, or later. | If you want to have multiple installations of IBM MQ, with one at Version 7.0.1, the Version 7.0.1 installation is automatically the primary installation. While IBM WebSphere MQ 7.0.1 is installed, you cannot change which installation is the primary installation. For information about this option and its implications, see Multiple installations of IBM MQ, one at Version 7.0.1 |
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Multiple installations: Version 7.1, or later. |
Version 7.1, or later. | Version 7.1, or later. | If you want to have multiple installations of IBM MQ at Version 7.1 or greater, you can choose whether to make one of the installations primary. For information about this option, see Multiple installations of IBM WebSphere MQ 7.1, or later |
| None | Version 7.1, or later. | ||