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What changes does HPC Pack make to the Domain Controller? RRS feed

  • Question

  • BACKGROUND:

    I began installation of a single head node on a clean Windows Server 2016 Essentials computer. Unfortunately, I applied the KB patch for Update 2 before finishing post-installation configuration of the head node. This caused a world of hurt. So I ended up starting over with a clean install of Windows Server 20016 Essentials.

    I could tell right away something was amiss, as the head node would not join to the domain. It turned out the problem is the old IPv6 address was still in the domain controller DNS records. Ok, that made sense. So I disabled IPv6 on the head node and was then able to join the head node to the domain. After joining the domain, I re-enabled IPv6 on the head node and verified that the DNS record on the domain controller got updated with the new IPv6 address of the head node (it did).

    By all measures, it appeared I finally had a "clean" head-node computer to start over with. I could ping the domain controller and all the other network resources using fully qualified active-directory domain names. So DNS resolution was working properly and the head node was identifying itself as a member of the domain.

    Then I started the HPC Pack 2016 Update 2 (full install). I realized something was still amiss, as a warning said that the computer was not joined to a domain or that it could not verify the trust relationship. The whole domain is a single forest on a LAN. So this was puzzling. Since it was a warning and I new the computer was joined to the domain, I proceeded with the installation anyway.

    The install completed successfully. But when trying to configure HPC Users and job administrators after the installation, I was unable to proceed. Clicking "Add User..." or "Add Job Administrator..." all resulted in error messages. Examining the HPCAdminMirror group, for example, I noticed all the domain users were displayed as long random-looking numbers instead by their typical display name. This usually happens when the system can't reach the active directory information on the domain controller.

    QUESTION:

    So the question is: "What changes does HPC Pack make to the Domain Controller?"

    It seems that simply starting with fresh install of Windows Server 2016 on the head node was not enough to get back to a "clean" state. Aside from the IPv6 entry in the DNS records (which I understand and makes sense), it seems there is other changes that were made to the Domain Controller during the original installation of the head node that has led to a failed second attempt at a "clean" installation.

    How do I restore the network and domain controller to a "clean" state without (hopefully) having to also reinstall the domain controller?


    Tuesday, April 16, 2019 6:39 PM

All replies

  • UPDATE:

    1. Deleted head node from active directory on the Domain Controller.
    2. Re-installed Windows Server 2016 Essentials on the head node.
    3. Head node will not join to domain.
    4. Disabled IPv6 on the head node.
    5. Head node joins to the domain.
    6. Enable IPv6 on the head node.
    7. Reboot.
    8. Configuring Windows Server Essentials wizard does not recognize that computer is joined to domain (even though System pane in Control Panel says it is) and attempts to finish configuring head node as domain controller.
    9. Disable IPv6 on the head node.
    10. Reboot.
    11. The wizard recognizes head node as joined to domain but doesn't recognize Domain Administrator credentials when asked to finish installation of Windows Server (as if it can't really see the active directory information).

    Clearly, it's a problem with IPv6 DNS resolution. Prior to the first failed installation of HPC Pack, I had been able to join all computers to the domain without these issues (IPv6 was enabled on all computers). All computers have been reformatted with a clean install except the domain controller.

    So what could HPC Pack have changed on the domain controller that might cause these issues?


    • Edited by Nate Hayes Wednesday, April 17, 2019 12:58 AM
    Wednesday, April 17, 2019 12:55 AM
  • If I configure the head node IPv6 DNS Server entry to use the IPv6 address of the domain controller, I don't experience the above issues.

    Before the first failed install of HPC Pack, I had all of the nodes configured with static IPv4 configurations (including the IPv4 DNS Server entry) and to obtain the IPv6 configuration (including IPv6 DNS Server entry) automatically. Indeed if I do ipconfig /all on the nodes that were joined before the first HPC Pack install, they report *only* the IPv4 address of the domain controller (there is no IPv6 DNS Server entry) for the DNS Server. Whereas now if I configure the head node to obtain the IPv6 DNS Server automatically, ipconfig /all reports *two* values for the DNS Server: first is an IPv6 address of fc00::1 and second is the IPv4 address of the domain controller.

    If I configure the head node IPv6 DNS Server entry to use the IPv6 address of the domain controller (instead of getting it automatically), then the domain join issues seem to go away, but the ipconfig /all shows two values for the DNS Server: first is the *full* IPv6 address of the domain controller and second is the IPv4 address of the domain controller.

    SUMMARY:

    Before first install of HPC Pack:

    • Nodes were configured to obtain IPv6 DNS Server automatically and were assigned only an IPv4 address (no IPv6)

    After the HPC Pack install:

    • Nodes configured to obtain IPv6 DNS Server automatically are assigned *two* values: fc00::1 and an IPv4 address (this configuration causes the domain join problems)
    • Nodes configured to use static IPv6 DNS Server are assigned two values: *full* IPv6 and IPv4 addresses of domain controller (this avoids the domain join problems)

    So for some reason, installing HPC Pack causes nodes configured to obtain IPv6 DNS Server address automatically to be assigned the fc00::1 value, which appears to be the source of the problems. Another way of saying it, installing HPC Pack requires configuring nodes with static IPv6 DNS Server entry.

    How to undo this change and revert to the original behavior?

    Wednesday, April 17, 2019 3:14 AM
  • I managed to install HPC Pack again on the head node using the static IPv6 DNS Server settings mentioned above. Same for some new compute nodes.

    On the head node, select Add Nodes but at the Select New Nodes page when selecting Default Compute Node Template, there are no nodes listed. All the compute nodes are on and HPC Pack installed.

    Help!

    Wednesday, April 17, 2019 6:36 AM
  • Node Manager service was not started on the head node for some reason. That let me add the nodes.

    Seems I'm back a functional installation. However, the original question remains. Since I had to reconfigure all the nodes with static IPv6 DNS Server values this time, why not before?

    Wednesday, April 17, 2019 5:50 PM
  • HPC Pack head node will create a ServiceConnectionPoint object in the domain, but I don't think it has something to do with the issue you met.

    And it doesn't make sense that HPC Pack installation will make your computer auto fetch a DNS server "FC00::1", I suppose your DHCP server returns this primary DNS server to the computers.

    So please check your DHCP server and configure the correct DNS servers.


    Friday, April 19, 2019 3:22 AM
  • I've reproduced the problem between two computers with clean installations of Windows Server 2016 Standard (one as new domain controller), prior to any installation of HPC Pack into this clean environment.

    So, you correct. Still trying to figure out the problem, but it's not HPC Pack related.

    Saturday, April 20, 2019 12:01 AM
  • Thanks for the update.
    Monday, April 22, 2019 4:58 AM