Checking Root Account Status

 

Checking Local Root Account Status

Run sudo passwd -S root: Look for the status letter in the output. An L means the account is locked (disabled), while a P means it has a usable password.
Check /etc/shadow directly: Run sudo getent shadow root or sudo grep root /etc/shadow. If the second field (the password hash field) starts with an ! or *, the password is locked and direct login is disabled. [1, 2]

Checking Remote SSH Root Login Status

Test the effective SSH setting: Run sudo sshd -T | grep permitrootlogin. If it outputs permitrootlogin no or prohibit-password, remote root access via password is disabled.
Inspect the configuration files: Check /etc/ssh/sshd_config and files inside /etc/ssh/sshd_config.d/ for PermitRootLogin no

Ubuntu Unsupported upgrades

 Unsupported upgrades

Sometimes do-release-upgrade isn't able to run the upgrade to the latest version and it shows an error similar to this:

An upgrade from 'eoan' to 'focal' is not supported with this tool.

If that happens, you need to download a version-specific upgrader, you can find the link at https://changelogs.ubuntu.com/meta-release.

You need to download the upgrade tool for the version you are upgrading to. For example, if you are upgrading to Ubuntu 20.04 (focal), you'll see the link on that page as follows:

UpgradeTool: http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dist-upgrader-all/current/focal.tar.gz

The download is an archive which contains an executable with the code name of the release. execute it to run the upgrade tool for that release. Note that the archive extracts everything in the current directory so you might want to create a directory for it to extract into:

# Downloads the upgrader, check the link above for the URL of the file for your release
wget http://archive.ubuntu.com/ubuntu/dists/focal-updates/main/dist-upgrader-all/current/focal.tar.gz
# Extract it into a new directory
mkdir upgrader
tar -xaf focal.tar.gz -C upgrader
cd upgrader
# Run the executable, the name changes based on the release
./focal

This executable works the same as do-release-upgrade. If you still get the error of the upgrade not being supported, you might need to make an intermediate upgrade to an earlier version.

Adicionar registro DNS windows linha de comando

 Usando o Prompt de Comando (dnscmd)Abra o Prompt de Comando como Administrador e utilize a seguinte estrutura para adicionar um registro do tipo A (endereço IP):
dnscmd . /RecordAdd <NomeDaZona> <NomeDoHost> A <EnderecoIP>
Exemplo prático: 
dnscmd . /RecordAdd meu-dominio.com meu-servidor A 192.168.1.50

O ponto . indica que você está gerenciando o servidor DNS local.
Usando o PowerShell (Add-DnsServerResourceRecordA)
Abra o Windows PowerShell como Administrador e execute o comando correspondente para a zona de pesquisa direta:
Add-DnsServerResourceRecordA -Name <NomeDoHost> -IPv4Address <EnderecoIP> -ZoneName <NomeDaZona>
Exemplo prático: Add-DnsServerResourceRecordA -Name meu-servidor -IPv4Address 192.168.1.50 -ZoneName meu-dominio.com