I have a SharePoint 2013 farm with multiple HNSCs, spread across multiple Web Applications. Recently a requirement came down to "copy" this farm and its content from the current URL/Domain site1.OldDomain.com to site1.NewDomain.com.

NewDomain.com will use different authentication (Claims with SAML) than OldDomain.com but all other infrastructure is identical: same virtual servers, same farm, same content, same content types, same user groups/permission, IA etc etc.

The requirement is that OldDomain.com remain in tact, operational and unaffected by NewDomain.com while NewDomain.com is being tested.  

My question is what is the most straight-forward way of copying a HNSC farm to a new set of host-named site collections?

Hi,

From your description, you migrating a Host-Named Site Collection (HNSC) From One Farm to another.

1. Backup the site collection.
2. Restore the site collection as a host-named site collection (the restore will create the site collection for you).

Refer to the following article about migrating a Host-Named Site Collection (HNSC) From One Farm to Another:

http://www.davidwesterfield.net/2015/03/migrating-a-host-named-site-collection-hnsc-from-one-farm-to-another/

http://blogs.technet.com/b/heyscriptingguy/archive/2013/12/19/migrating-host-named-site-collections.aspx

Best Regards,

Lisa Chen