MrPool

Q: Server Migration: "Verify DNS mappings exist"

I am aiming to migrate from an older server computer running 10.6.8 to a MacMini running 10.10.5.

 

I'm using what seems like the definitive guide from Apple, even though it only appears to address upgrades to Mavericks:

 

OS X Server: Upgrade and migration from Lion Server or Snow Leopard Server - Apple Support

 

A key question I have is about this document which is referenced in the one above:

 

OS X Server: Steps to take before upgrading or migrating the Open Directory database - Apple Support

 

"Verify DNS mappings exist

Verify that both A and PTR (forward and reverse) DNS mappings exist, and will exist for the computer's hostname during the upgrade process. The interface with the IP address that the hostname resolves to must be active during the upgrade process.

Do not take the computer offline for the upgrade process.  If this is necessary, move the computer to a private network with a working DNS, where it can keep its IP address, but is not accessible to the world."

Here's my issue:

My server is the DNS server for our internal network. That's a key role, that's why we run a server internally. Since the recommended migration path is to upgrade the existing server, using the same name, I don't think we can leave the old server online while we bring up the new server.

So I don't see how to migrate the server if it is the DNS server and requires a DNS server already up and running to do the migration.

Thanks for any insights into this issue, and any other pointers which would make this go easier.

Mac mini, OS X Yosemite (10.10.5)

Posted on Oct 29, 2015 12:01 PM

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Q: Server Migration: "Verify DNS mappings exist"

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  • Helpful answers

  • by Linc Davis,

    Linc Davis Linc Davis Oct 30, 2015 9:22 AM in response to MrPool
    Level 10 (207,990 points)
    Applications
    Oct 30, 2015 9:22 AM in response to MrPool

    If you use the DNS service, and the server is a DNS client of itself (likely), temporarily change the primary DNS setting in the Network preference pane to another name server, such as your ISP's name server or a public DNS service, until the update is complete. Remember that you must Apply any change in the network settings before it takes effect.

  • by MrPool,

    MrPool MrPool Oct 30, 2015 9:44 AM in response to Linc Davis
    Level 1 (0 points)
    Oct 30, 2015 9:44 AM in response to Linc Davis

    Linc, thanks for the reply. Yes the server runs DNS and is a client of itself as you correctly guessed. Of course, on the local network the server has an address in the 192.168.x.x range and the public DNS resolves to something more like 70.98.x.x.

     

    So while I'm migrating in that local subnet, DNS is going to be responding with an external IP address. I'm baffled that this is somehow helpful to the setup, but if that's what's required I guess I'll give it a try next time I'm onsite.

     

    Thanks,

     

    David