After upgrade from Drupal 6 to Drupal 7 search does not work Same server, upgrade went well and site is stable however it won't index content even after clicking on re-index. Crons are running just fine on server, checked on the MySQL database and all the tables related to search (search_dataset, search_index, search_total etc) are all empty. I have tried turning all modules off, emptying cache, turning search on off, nothing works.

I would really appreciate if anyone knew a way around this.

Kind Regards

Javier
Reindex the search data in config->search->setting and run cron again and again upto the index percentage reaches 100%.

This will solve your issue.

You can also do it via drush to get around limit on the number of items that get indexed per cron run.

$ drush help search-index


Index the remaining search items without wiping the index.
and/or

$ drush help search-reindex


Force the search index to be rebuilt.

Options:
 --immediate Rebuild the index immediately, instead of waiting for cron.