Install Ubuntu-18.04 on a NVMe disk

The price of NVMe disk getting closer or similar to SSD, most recent servers have only NVMe disks.

Unfortunately, installing Ubuntu-18.04 on such server triggers the error

Validation error: 'nvme.XXXXXX' is not valid under any of the given schemas in [...]

This issue has been fixed in but is not yet backported on 18.04.3

If, you need to install 18.04, because for example of the NVIDIA driver support, the fix is to:

  1. flash a usb dongle with ubuntu-18.04
  2. after booting on the usb dongle, go to a terminal with Alt+F2 and enter
    sudo snap refresh --edge subiquity
  3. next, go back to main screen with Alt+F1 and start the installation.


Hopefully, 18.04.4 should have the patch.



Windows preparation for remote control with Ansible

Enabling Admin account

net user administrator /active:yes
net user administrator MyPassword

Enable Remote access and configure firewall

# To be done on both side


# To be done on both side 
winrm enumerate winrm/config/listener
winrm delete winrm/config/Listener?Address=*+Transport=HTTP
winrm delete winrm/config/Listener?Address=*+Transport=HTTPS


$myFQDN=(Get-WmiObject win32_computersystem).DNSHostName+"."+(Get-WmiObject win32_computersystem).Domain
New-SelfSignedCertificate -DnsName $myFQDN -CertStoreLocation Cert:\LocalMachine\My
$thumbprint=@(Get-ChildItem -Path Cert:\LocalMachine\My | Where {$_.DnsNameList -match "$myFQDN" }).Thumbprint
winrm create winrm/config/Listener?Address=*+Transport=HTTPS "@{Hostname=""$myFQDN""; CertificateThumbprint=""$thumbprint""}"
Set-Item -Path WSMan:\localhost\Service\Auth\Basic -Value $true 

Host file

In a file name hosts.cfg

server1 ansible_host= ansible_user=Administrateur ansible_password=secure_password
server2 ansible_host= ansible_user=Administrator ansible_password=secure_password


And in the playbook


# This playbook tests the script module on Windows hosts
- name: Run powershell script
    - server1
    - server2
    nsimul: 8
    results_dir: C:\results{{ nsimul }}
  gather_facts: false
  tasks: ...

Unbrick and update a J-Link V8 clone

You can buy a Segger JTAG J-Link clone for few USD on ebay, aliexpress, dx, ...

If you try to update its firmware with the official Segger tool, you'll brick the probe.

Don't worry, smart people have already put a checklist to restore a working firmware and even update it to the latest official version. I just put all the needed info into one single page.

Continue reading Unbrick and update a J-Link V8 clone