When your company is upgrading your internal business software, the temptation is always to upgrade directly. Legacy upgrades involve trying to upgrade the software without changing any of the data or configuration files. This is often successful for minor upgrades like security patches. However, major version upgrades are almost always more effective when the system is completely rebuilt with the new software.
However, you don’t have to accept generalizations. It’s worthwhile for IT teams and business owners to understand why legacy upgrades are less satisfactory and often unsuccessful compared to a professionally upgraded and migrated system.
1) New Versions Have New Configuration File Settings
One of the leading problems with legacy upgrading is that software companies change how they do things on the back-end. The new features, protections, and capabilities of the upgraded software naturally require new and improved configuration files. Unfortunately, the configuration files already on your system may cause errors to your upgraded software.
It’s important for new software to generate custom configuration files, tailored both to the software and business needs. While the old config files may have been optimized for your business and the previous version, they can actually cripple the effectiveness of your new software version.
2) System Integrations Change as Legacy Software Stacks Upgrade Unevenly
Another problem with legacy upgrades is that businesses rarely use a single piece of software independently. This is why business tech refers to “stacks“. A simple stack example used for websites is LAMP, Linux, Apache, Mysql, and PHP. Also, upgrading PHP without noting how that affects other software elements can cause errors. Particularly since the config files of the other software often reference the exact version of its stack-mates at the time of the original install.
It’s actually faster in many cases to install a whole new stack using the latest versions of everything than try to comb through your legacy config files changing how the unevenly upgraded software relate to each other in the stack.
3) Not All New Versions Have a Legacy Upgrade Option
The idea of legacy upgrading comes from the fact that some software includes a special script designed for legacy upgrades. There are brands and programs that specialize in making legacy upgrades possible. These scripts are designed to comb through your old configuration and data files, programmatically changing any settings, variable names, and data structures.
However, not all programs have a legacy upgrade option, and trying a legacy upgrade without a designer-guided script is much more likely to produce errors because these settings, variables, and structures have not been updated. Also, these legacy upgrade scripts usually do not include upgrades for related software in a stack.
4) Often New Versions Require an Entirely New Module Set
If you are using business software that includes a stack of additional modules that customize the appearance and functionality, this is another cause of tricky legacy upgrades. Modules are little software packages that add to or alter the original code of the software program. However, rarely are modules upgraded at the same rate or toward unified functionality.
For businesses upgrading a core software set that is augmented by many modules, it would be nice if your legacy upgrade worked perfectly to maintain module connections. But they rarely do. In fact, the new version might be associated with an entirely new set of modules that will be the new ideal for your business, or you might need to individually upgrade the modules that are supported by the new core version and find replacements for modules that are no longer supported.
Learn More About Why Legacy Software Upgrades Often Fail
Legacy upgrades are rarely as rewarding as they are tempting. Most businesses will lose more time troubleshooting the discrepancies in settings and stack-integrations than they would simply rebuild the system with a fresh upgraded stack and expert data migration. To learn more about successful software upgrades, please contact us to speak with one of our technology consultants.