Migration from SharePoint 2013 to SharePoint Online

Permissions, Assessment and Reports are the common prerequisites for any Migration. In my case, we used Share-gate Migration Tool and completed the migration from SharePoint 20103 to SharePoint Online successfully.


Recommended Permissions
Here are the recommended SharePoint permissions to use with the following features:

Copy Structure: Site Collection Administrator rights are recommended both on the source and the destination site collections in order to take advantage of all the copy options. If you are copying site collections from the web application, Farm Administrator rights are recommended both on the source and the destination Farm. For migration of managed metadata and objects where copying this data is necessary, term store administrator access is also needed.

Copy Content: Full Control permissions on both the source and destination Sites (if applicable) as well as on the selected list or library are recommended to be able to take advantage of all the copy options. Term store administrator permission is necessary for the proper migration of all managed metadata.

Management features: In order to fully exploit all of the Management module's capabilities the following permission sets are also required: Farm administrator, site collection administrator as well as full control on the web application.

Note: For OneDrive for Business operations, it is important to note that the user being used when connecting to either the source or destination server must also be set up as an administrator for every user's MySite.

Copy User Alerts: In order to copy User Alerts the permission "Manage User Alerts" must be granted to the user doing the migration at the source and destination sites. The server extension must be installed on the source and destination sites.

Remove read-only Site Collection Lock: The Read-only lock should be removed on your source Site Collection before running a migration action. Some SharePoint services do not respond correctly when the Site Collection is on read-only mode (even if they are only used to read information), and the requests will not be processed as intended.

Not removing the read-only lock will mostly affect the structural parts of your environment, like Web Parts and Site settings, but the behavior is unpredictable and is may affect more overall.

Assessment
Microsoft is providing the SharePoint Assessment and Identity Management tool (free of cost) for SharePoint 2013 servers to assist in migration to SharePoint online.

Find more details in the below link.
https://docs.microsoft.com/en-us/sharepointmigration/migrate-to-sharepoint-online
Even if you're technically migrating from one version of SharePoint to another, they aren’t exactly the same. First, you have to take into consideration that there are different plans you can subscribe to and each with a set of features available. In my case, we were going with Office 365 E3 plan which includes SharePoint Online.

I did research and check to make sure the features we were using in SP 2013 are still available in our new Office 365 E3 plan.

Microsoft has a very detailed article which shows every single feature in a complete Edition Comparison Chart of SharePoint 2013, both On-Premises, Online and Office 365.

Please go thru SharePoint Online Limits as per Microsoft (below link).
https://technet.microsoft.com/en-us/library/mt842345.aspx

Share-gate Migration Tool
In my case, we were using Share-gate Migration Tool to migrate from SharePoint 2013 to SharePoint Online. It has many built-in reports and we can also create custom reports. We have Inventory option to generate inventory report.

We need to run the the below given reports and make sure everything is cleared.

• Orphaned User Report (we need to go thru and clean Orphaned users) 
• Checked Out Documents Report (We need to check in all the Checked out Documents before starting Migration) 
• Unused Site Report (discuss with Owners and delete unwanted sites) 
• Large Document Report (keep an eye on these files after migration too) 
• Limited Access Report (run a report and clean them)

There is a new feature in Share-gate called Insights, where you can run it on a specific farm and get some info about Missing Administrators and missing Site Owners.



Once all the above prerequisites are completed, We started the migration of Content from SP 2013 to SharePoint Online using the steps given in below link.

https://support.share-gate.com/hc/en-us/articles/115000640388-Walkthrough-Copy-Content