How to manage DNS switch for host named site collections

Question

We are upgrading to 2016 and migrating some web applications from 2010 to 2016 using Database attach, with no 3rd party tool but just using Powershell commands. In 2010 we have 2 web applications, with several site collections in them which we decided to configure as Host Named site collections(HNSC) for capacity management reasons. So basically we are demoting 2 web apps as Host named site collections. The problem is, with HNSC's AAM (Alternate Access Mappings) is not available, and without AAM I don't know how to manage the minimal service interruption during the go-live. Does anyone know a way to redirect HNSC's ?

For example, www.my2010.com is current web app address and root site address. I am implementing this root site as HNSC in 2016.

Will it work, if I create HNSC as www.my2010.com then do the DNS switch from old 2010 server to new 2016 servers?

Answer 1

It looks like you do not add/remove/change the URLs. You just use another way how those URLs exist (WebApplication vs. HNSC). So I think you do not have a special challenge compared to a migration without HNSC.

• Do NOT use a temporary URL like www.my2016.com during the migration phase and then change it back to www.my2010.com during productive migration. I have seen lots of pain with that.
• I think you will set up the 2016 system and do a testmigration first. Get access to migrated content by modifying the HOSTS-File on your SharePoint 2016 Servers and Test-Clients. www.my2010.com should point to your SP2016 WFE-Servers IP-Address.
• Productive migration could look like this:
  • Take SP2010-Databases to read-only mode. Keep DNS-Config, so your clients can still access SP2010.
  • Copy the databases to SP2013 and SP2016. Convert them to HNSC in SP2016.
  • After migration process is complete, change the DNS-Record to IP-Address of your SP2016 WFE-Server. You can now remove the entries in the HOSTS-Files. Clients will now reach SharePoint 2016.
  • Very often the old system must still be available for administrators to compare stuff or check if errors existed already in the old environment. Achieve this by modifying HOSTS-File on SP2010 servers and point it to the SP2010 WFE IP-Address.