Creating an Oracle RAC on Azure cloud with FlashGrid SkyCluster

Step by step instructions for configuring Bastion host in Azure

Configure Bastion host for Azure VM

What is Azure Bastion?

The Azure Bastion is PaaS service that you create inside your virtual network. It provides secure RDP and SSH connectivity to all of the VMs in the virtual network in which it is provisioned so that your target virtual machines do not need a public IP address.

Configuration Steps:

1. Connect to the Azure portal and choose the VM to connect to.

2. From the left panel, choose Bastion under the Operations section, or click Connect from the Overview section.

3. To associate a virtual network with a Bastion, it must contain a subnet with the name AzureBastionSubnet. On the following page, click Manage subnet configuration

4. Add subnet named AzureBastionSubnet

5. After configuring subnet, click link rac1-vm – Bastion in the upper left corner. And then click Create button.

6. Connect to the VM via Azure Bastion

If you have ssh key based authentication, enter correct username and choose the right private key file.

Please note, that the private key file should be in PEM format. If you get the following error message, it means your key file is not in the correct format:

 If so, convert it using ssh-keygen (for windows PuTTYgen) :

$ ssh-keygen -p -m PEM -f my_private_key

Choose the key file again and click Connect.

“kernel: serial8250: too much work for irq4” potential problem caused by Azure OMS Agent

Problem:

There are a lot of warnings “kernel: serial8250: too much work for irq4 ” in /var/log/messages and are likely your system experiences stability problems. And can lead to Oracle cluster node evictions.

Cause:

The problem was related to Azure OAM Agent pushing very large messages to serial console. The problem was introduced by the latest update of the Azure OMS agent.

Temporary Solution:

Temporarily remove OMS Linux Agent Extension until Microsoft resolves this bug:

1. On Azure portal click the link of the affected VM.
2. Click the “Extensions” section.
3. Click the OMS Linux Agent in the list.
4. Click the “Uninstall” button at the top

When you make sure that OMS agent bug is fixed (should be verified with Microsoft support), then you can reinstall the pluggin.