Upgrade process from SharePoint 2010 to SharePoint 2013

To upgrade from SharePoint 2010 Products to SharePoint 2013, you use the database-attach method to upgrade. In the database-attach method, you first create and configure a SharePoint 2013 farm. Then you copy the content and service application databases from the SharePoint 2010 Products farm, and then attach and upgrade the databases. This upgrades the data to the new version. Site owners can then upgrade individual site collections.

TechNet Article: http://technet.microsoft.com/en-us/library/cc262483.aspx

Upgrading from SharePoint 2010 to SharePoint 2013 Step by Step:

This is a step by step guide on upgrading a SharePoint 2010 site to a SharePoint 2013 (Customer Preview) and as with any Beta release is subject to change. For further information on planning and upgrading content and services to SharePoint 2013 you can visit the recently published TechNet site here:

Also make sure to check out Bill Baer's great post on Upgrade, and special thanks to Bill for sharing his custom solution used for this post.

1.      Add and deploy any required O14 custom solutions in your SharePoint 2013 farm, notice that all O14 solutions being deployed under 14 hive but eventually it's recommended to migrate the custom code to O15.

2.      Backup and restore the SharePoint 2010 content database to your SQL Server hosting SharePoint 2013 farm.

3.      Run Test-SPContentDatabase cmdlet to identify missing components along with potential errors and related warnings. Check the upgrade log and deploy any missing components and re run the cmdlet to verify.

4.      Attach the content database to the desired web application using Mount-SPContentDatabase cmdlet.

5.      After successfully mounting the content database to web application, the site should be accessible in 14 mode.

6.      To upgrade the site simply click on "Start now" link on the toolbar, you can also go to SiteUpgrade page from Site Setting page as well.

7.      Click on "TRY A DEMO UPGRADE" link to verify the site collection upgrade (This step can be performed by Site Collection Administrators, farm admins can run

Request-SPUpgradeEvaluationSiteCollection cmdlet as well).

8.      Provision a temporary site collection to validate the site post-upgrade.

9.      An email should be sent out to Site Collection admin when the temporary site is provisioned.

10.      After validating the temporary site we upgrade the site by going to SiteUpgrade.aspx page and clicking on "Upgrade the Site Collection" button (Farm admins can run Upgrade-SPSite cmdlet as well).

11.      During the upgrade The SiteUpgrade.aspx page shows the progress and provides a link to an upgrade log for troubleshooting purposes.

12.  Your site collection should now be accessible in 15 mode along with all new capabilities enabled in the farm and for the hosting web application such as Social and Office Web Apps.

Curtsey: Zillions Thanks to Ali Mazaheri for his explanatory Post.

If you have any issue during the upgrade do let me know. I would be my pleasure to work for you.