I have successfully performed database upgrade with a fresh magento 18.104.22.168 installation.
Followed instructions from manual upgrade using fresh install and original database by Brent Peterson, with some differences.
Exact procedure follows
on Live Server:
1. emptied and disabled magento cache
2. emptied database cache
3. updated indexes
4. database dump
5. www root dump
on Test Server
1. cloned environment (virtual host, apache modules, PHP and MySQL version)
2. installed magento 22.214.171.124 pointing to DB `fresh`
3. deactivated cache
5. imported live db to `live`
6. updated local.xml to let fresh magento point to `live` database
7. files copy from live dump (using “merge” principle, only add not existing files)
--- app/code/community/* (ALL modules files, since previous tests failed with not all modules copied)
--- app/code/local/* (same as above)
--- media/* (media/catalog/product/cache skipped)
--- translation files skipped atm
8. properly chown-ed and chmod-ed
9. launched `nohup php index.php`
10. after 12 hours, the script exited with zero bytes output
just in case anyone is wondering: I have chosen this procedure because live magento files have been messed up by previous developers, creating unexplainable bugs.
well, the upgrade was successful!
Frontend seems to be almost PERFECT!
But I got some modules related issues (still checking and counting)
1. All the modules have their own menu labels, so modules exist and get initialized, but in magento connect there are no modules installed (only base modules appear)
2. Group Deals module’s pages are blank (only generic page content is shown)
3. Amasty Product Attribute Grid fails to initialize: got a “Uncaught ReferenceError: pAttribute is not defined” error in JS console
I am about to establish contact with modules developers, but I’m worried about the magento connect issue.