When we plan for an upgrade from MOSS 2007 or WSS 3.0 to
SharePoint 2010 Products, we have different upgrade approaches as building
blocks that can be used for optimal upgrade approach.
We can upgrade multiple content databases at the same time, which
results in faster upgrade times overall than an in-place upgrade. For more
information on Upgrade Process please refer to http://technet.microsoft.com/en-us/library/cc262483(office.14).aspx
In-place upgrade: Use this approach to install the
new version of SharePoint 2010 products on the same hardware that is used for
the previous version. Upgrade the content and settings in the server farm as
part of a single process.
Database attach upgrade: Use this approach to upgrade the
content for the environment on a separate farm. It doesn't upgrade any of the
services or farm settings. Content databases can be upgraded in any order and
can upgrade several databases at the same time. Using this approach, it’s
possible to attach a Shared Service Provider database during DB attach upgrade,
this will upgrade the profile information in the database. Using this approach,
it’s not possible to upgrade the search database.
Hybrid approaches: A hybrid approach lets us to take
advantage of in-place upgrade's ability to upgrade content and settings, while
we take advantage of the speed of a database attach upgrade. The
advantages of this method is
1) Farm wide settings
can be preserved and upgraded
2) Customization are
available in the environment after upgrade, although manual steps may be
required to upgrade or rework