Iam a SharePoint administrator for X Company. I plan to upgrade the Microsoft Office SharePoint Server 2007 server farm to SharePoint Server 2010. SharePoint Server 2007 Configurations The SharePoint Server 2007 server farm contains the servers configured as shown in the following table.
Server1 and Server2 are load balanced by using a hardware load balancer. The server farm has the following configurations: .Two Shared Services Providers .Two Web applications named Web1 and Web2 .A 500GB site collection in Web1 .A 700GB site collection in Web2 .Microsoft Office PerformancePoint Server 2007 data and dashboards To prepare for the upgrade, I deleted 200 GB of text documents from Web1 and 400 GB of text documents from Web2.
Technical Requirements : .Users must be able to access upgraded and nonupgraded sites during the upgrade process. .All PerformancePoint data and dahboard information must be migrated to SharePoint Server 2010.
Security Requirements: 
sers must be able to access all documents during the upgrade process.
I am evaluating whether to implement an inplace upgrade to SharePoint Server 2010. I need to identify how many index partitions will be created during the inplace upgrade. How many index partitions will be created?
Can somebody explain me more about index partitions?
PD: This question is adjusted from a training question for SP 2010 Certification.
Your question is only how many index partitions are created? Automatically? None. Index partitions only spread your search application index over several partitions, hence speeding up your searches (and decreasing the size and needed RAM for the DB on the server holding a subset of your index). There is a limit of 20 index partitions per search application.
You can read some about Search Architecture and about indexing.