SharePoint 2013 - Upgrade and Migration

Upgrade Features Overview

Words like "upgrade" and "migration" may have brought chills to SharePoint administrators and IT managers in the past, but SharePoint 2013 looks to ease the pain of this process. Whether you’re coming all the way from WSS or MOSS, SharePoint 2013 has processes in place to make the transition easier while protecting your data.

The in-place upgrade option found in SharePoint 2010 is gone. The in-place version to version upgrade from SharePoint 2007 to SharePoint 2010 option was generally avoided because a mid-migration failure could lead to data corruption and people's jobs. The database attach method is now the primary option and improvements have been added to safeguard data while accelerating migration speeds.

Some Enhancements for SharePoint 2013 Upgrades:

Safer Upgrades with Site Collection health checks and evaluation sites for preview
Reduced Outage Duration by upgrading site collections separately from databases
Deferred Site Collection Upgrade allows site collection administrators to control when the site collection upgrade occurs as well as when the user experience switches from 2010 to 2013

SharePoint 2010 Customization upgrades can wait as they are installed alongside the SharePoint 2013 bits
A System Status bar at top of screen (upgrade in progress, maintenance in progress, read only data)
Improved Upgrade Logs with Specific Error Codes and separate files for each site collection upgrade