Migrating DHCP from 2003 to 2012 R2

This post will likely fall on deaf ears since no one out there is still running Windows Server 2003 right?

Well we are for our oldest DHCP server. Better yet it’s 2003 Standard (non R2) which means I can’t installed Active Directory Management Gateway Service which would allow me to remotely access DHCP on the 2003 server via PowerShell 5.1 running on a different box. Newer versions of PowerShell include support for working with DHCP. PowerShell 2.0 (latest available for Server 2003) does not support these commands.

Googling around found me the standard recommended way of migrating DHCP subnets.

On the source machine run:

This will export all of the current leases and reservations in the scope into a text file, you can then transfer the text file over to your new DHCP server and run the following to import it:

The downside to this method is that it causes a temporary outage of your DHCP server during the import/export. I just migrated 80 odd subnets during the day and the outages were so short no one noticed.

Alright so that was the easy part.

In addition to 80 standard DHCP scopes we have 4 superscopes that also need to be migrated.

Attempting to migrate the superscopes using the above method failed. When I attempted to import the scope into the destination DHCP server I got the error “TLS supported but not configured”.

The first post I found for this error in Google links to a Technet discussion where someone states “No, you cannot direct migrate windows server 2003 DHCP/DNS to windows server 2012 DHCP/DNS.”. Clearly not an accurate statement since I’d just migrated 80 standard scopes.

So here I am. I cannot move 4 super scopes using the netsh method, I cannot use PowerShell because the 2003 server is to old and I do not want to upgrade it to 2003 R2 for multiple reasons (did I mention it’s a Domain Controller to?).

What I ended up doing was building a new Windows 2012 R2 Standard box, joined it to our domain so I could remotely access it and have the benefit of domain logins for accessing resources across our network and then installed DHCP on it. Immediately after the DHCP Server installation completed I went into the Windows Firewall and blocked DHCP just in case.

Then on the old DHCP server I ran this command:

I then transferred the all.txt file over to the DHCP server I just built and ran this:

and ended up with a complete copy of my old DHCP server on my temporary DHCP server including my superscopes, no errors.

Now I can use PowerShell to finish this up. On the temporary DHCP server I ran this:

transferred SUPERSCOPE1.xml to the new DHCP server and ran:

And bingo. Superscope successfully migrated from 2003 to 2012R2 with a small middle step.

If you screw up or need to do this in batches over time you can quickly and easily wipe everything out on the temporary DHCP server by doing the following:

  1. Stop the DHCP service
  2. Delete the contents of C:\Windows\system32\dhcp
  3. Start DHCP servoce

You’ll end up with a blank DHCP server that you can re-import a fresh copy of your old DHCP server into.

After vCenter 6.5 U1g newly cloned VMs report “HA not enabled”

Our environment is:

  • vCenter 6.5 U1g (8024368) running on a Windows Server 2008 R2 Standard VM (we’re moving to an appliance once we go 6.7)
  • vSphere 5.5 7504623, 8 node cluster

Since upgrading to the latest vCenter every new VM we clone into our production cluster reports “The virtual machine failed to become vSphere HA Protected and HA may not attempt to restart it after a failure”

After contacting VMware Support they informed me that this is a known issue with the versions of vCenter and vSphere we’re using and to upgrade to vSphere 6.0 or 6.5.

Since vSphere 5.5 is EOL in September no patches are coming to resolve this.

It also turns out the issue is a GUI issue only. The VMs displaying this error are still protected via HA and will recover fine if a host goes down.

A workaround for the issue is to disable/enable HA. Doing so will clear the error.

How to replace the boot volume on a RaspberryPi

Just ran into what I think is called the “rainbow screen of death” where a fully functioning RaspberryPi running Raspbian stopped working on me after a reboot.

I know my MicroSD card is good quality and I wasn’t mucking with the boot file system before the reboot so it baffled me why things would just stop working.

I ran then MicroSD card through SpinRite and that didn’t solve the problem. If I connected the microSD card to another PC all the files were there.

Based on my research I found this happens from time to time where something goes wrong with the /boot volume. I could have just re-loaded and re-setup my RPi (it would have taken less time at this point) but I decided I wanted to try and fix it with out losing all of my data.

This is what worked for me:

  1. Image a fresh spare microSD card with the same distro of Raspbian you’re using on the non-functional microSD
  2. Connect the non-functional microSD to the same PC you have your freshly imaged microSD connected
  3. In Windows there is going to be one partition (disk) under My Computer you can actually view, that’s the boot partition
  4. On the non-functioning microSD copy ‘cmdline.txt’ and ‘config.txt’ to some place safe on your computer
  5. Copy the entire contents of the boot partition from the new microSD to the bad one overwriting all files when prompted
  6. Copy the backups of ‘cmdline.txt’ and ‘config.txt’ on to the bad microSD

If you’ve never run ‘rpi-update’ then you’re done. You should be able to put the microSD into your RPi and it will boot again.

If you have run ‘rpi-update’ you have a bit more work to do.

  1. Go to https://github.com/raspberrypi/firmware/releases and download the release that matches the date of the last time you ran rpi-update
    Note: If you don’t know when this is you might be able to boot the RPi now, login locally and dig through your ‘history’ or look at the date/time stamps on the files in /boot
  2. Extract the downloaded file
  3. Copy the contents of firmware-#.#######\boot into \boot on your bad microSD overwriting all files when prompted

Now you’re done. You should be able to put that bad microSD back into a RPi and have it boot

Once your RPi is backup and running I highly recommend manually running a ‘rpi-update’


How to remove the NetApp Host Utilities hotfix check

Sick of the hotfix requirements for NetApp Host Utilities? Me to.

On a test/dev server I have I’ve been experimenting with Veeam, iSCSI, ReFS and Server 2016. I wanted to run the NetApp Host Utilities against my Server 2016 box and was told I was missing Q3197954:

Problem is this 2016 server is fully patched and if I go manually download Q3197954 (which appears to be a previous rollup) I can’t install it on my fully patch server.

On a hunch I figured I might be able to crack open the MSI and find a way around the hotfix check and I was right. Here is how you do it:

  1. Download and install Orca MSI Editor (Alternate Download)
  2. Download the NetApp Host Utilities package from https://now.netapp.com/ (v7.1 as of this writing)
  3. Launch Orca and open the MSI file with it
  4. Select ‘InstallUISequence’ on the left and then click the ‘Sequence’ column on the top right to sort by lowest value first
  5. Locate ‘CheckMSHotfixes’, right click on it and choose ‘Drop row’
  6. Click ‘Save’
  7. Close Orca
  8. Copy the edited MSI to your server and run the installation as per normal

Digging around the MSI a bit I found references to “IGNORE_HOTFIX_CHECK” listed. I suspect it’s some kind of flag or environment variable that could be set to accomplish the same thing but I was unable to find any documentation on how and a few guesses around using environment variables didn’t pan out so I decided to stick with the above solution.

A note of caution. This is likely 100% unsupported by NetApp and if they found out you did this to get the Host Utilities on your server you might run into support issues.

Importing a OVF exported from vCloud into VMware Workstation fails

We’re backing out of a vCloud provider and trying to drag our VMs back into our local vSphere cluster.

I’ve used ovftool to export our VMs from vCloud into OVF templates. I then import the OVF into VMware Workstation 14 and from there drag/drop the VM into our vSphere cluster. There is likely a way to get the ovftool to export in a format that will work directly with vSphere but since this is working I’m just going with it.

This process worked fine on all of our VMs until I got to a group of them that had access to an extra network in vCloud. When trying to import these VMs into VMware Workstation I get the following error:

The source contains more than one network. This target supports at most one network.

I cracked open the ovf file in a text editor and found this near the very top:

In here you can see two networks, “myorg-it-pa-protected” and “server-net” on Line 3 and 6

The networking configuration doesn’t really matter to me since it doesn’t match with our vSphere deployment all I want to do is get these VMs imported. I’ll edit their networking afterwards.

I ended up deleting “myorg-it-pa-protected” by taking out lines 6-8 and lines 29-45. I then save/closed the OVF file and ran it through a hashing app to get the files SHA256 value.

I then opened the .mf file that sits in the same directory as the OVF file and updated the SHA256 entry for the OVF file. I was then able to import my VMs into VMware Workstation.

On Mac/Linux you can use “sha256sum <filename>” to get the SHA256 value of the edited OVF file. On Windows I use tools like HashTab and HashCalc OR if you have the Linux Subsystem installed on Windows 10 you can just use “sha256sum <filename>”.