Is your Linux instance not booting after changing to Nitro-based instance type? Our Support Team is here to help you out of this fix.

If your Linux instance refuses to boot after changing from Amazon EC2 to Nitro-based instance type, you are in the right place. Read to find out what our Support Engineers have to say.

Dealing with Linux instance not booting after changing to Nitro-based instance type

There are a number of reasons why your Linux instance is not willing to boot after changing to a Nitro-based instance. Let’s take a look at some of the common reasons:

• The ENA module is not installed on the instance.
• The enaSupport attribute is not enabled for the instance.
• Either the NVMe module is not installed, or it isn’t loaded.
• The file systems may be mounted at boot time in the “/etc/fstab” file via a device name. The file systems have to be mounted using UUID/Label.

Resolution: Linux instance not booting after changing to Nitro-based instance type

Enabling ENA:

• First, verify if ENA is enabled or not.
• After that, run the modify-instance-attribute if ENA is disabled.

Running NitroinstanceChecks script:
This script verifies the instance and offers a pass or fail status to the following requirements:

• Verifies the installation of NVMe module on your instance.
• Additionally, it checks the installation of ENA module on your instance.
• Furthermore, it looks for block devices mounted with device names by analyzing /etc/fstab
  

Moreover, this script runs on Amazon Linux, Amazon Linux 2, Red Hat Linux, CentOS, Red Hat Enterprise Linux, Debian, and Ubuntu.

You can run the script with these steps:

1. First, create an AMI of the instance before making any changes.
2. Next, change the type of instance to its original type.
3. After that, download the script to your instance.

   # chmod +x nitro_check_script.sh

4. Then, run the following command as sudo or root user:

   # sudo ./nitro_check_script.sh

Next, when prompted to type y or n, enter y to regenerate and modify /efc/fstab file. Additionally, it will also replace each partitions’ device name with its UUID. Here is an example of a successful output:

------------------------------------------------
OK  NVMe Module is installed and available on your instance
OK  ENA Module is installed and available on your instance
OK  fstab file looks fine and does not contain any device names.
------------------------------------------------

Once the requirements are met, change to a Nitro-based instance type.

[Need further assistance? Bobcares is at your service.]

Conclusion

In brief, we observed what to do if the Linux instance is not booting after it is changed to Nitro-based instance type from the proficient Support Engineers at Bobcares.