We have a crm 4.0 database of over 800GB and out of which attachments are occupying around 620GB. While upgrading to crm 2011 below are the issues i am facing any suggestions on how to reduce the time.
1. Step: Handle attachment upgrade after pass 1 is taking 8 hrs.
2. Step: upgrade indexes is taking more than 1 day and still continuing.
I had followed all the recommended options from Microsoft described in below links and had set OptimizeOrgImport to 1 and had rebuild indexes and updated the stats.
I don't think is much more that you can do to shorten the upgrade time. An 800GB database is very large. Is there anything you can do to
reduce the size of the database before the upgrade. Have you removed entries for asynchronous jobs etc.? This article has some info
Also, check the size of the CRM database tables in SQL Server Management Studio to see which tables have the most data (apologies if you've already done this) to help you focus attention on particular entities.