Upgrading MediaWiki can be a daunting task.
And, on a large wiki, it can take quite some time to rebuild data (which is required for Semantic MediaWiki)[1][2]
We have some detailed notes on prior upgrades like
eQuality Technology offers an automated DevOps approach to upgrades; and even running multiple versions if you require a legacy version (in a private wiki where there is less security concern). See https://QualityBox.us
References
- ↑ http://wikimedia.7.x6.nabble.com/When-is-it-required-to-run-rebuildData-php-td5074165.html
- ↑ Even on a small wiki, it took 6 hours to rebuild the data when the host was only running with 2GB of RAM