Hi, I wrote a post a few weeks ago with regard to Sitecore upgrading from 7.2 to 8.1. Everything went well, except I couldn't get Experience Profiles from historical data. I contacted with Sitecore support and after a few weeks I received the script for xDB's Contacts collection. I ran that script, performed the report db rebuild process (which is described here ) and the result was more than 3 million document in sitecore_analytics_index. So everything is working well after the upgrade process . Here is the mongo script:
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