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/Instance upgraded from t2 to t3 is not booting up/

Instance upgraded from t2 to t3 is not booting up


Hi, The instance in question is t3.medium instance in eu-west-1b region. The instance has been upgraded from T2 to T3 a couple weeks ago. It is set to start and stop daily but in the last 2 weeks - it happened the 2nd time already it is not able to boot. This problem is not daily but I would say weekly. The instance was fine yesterday but today it got stuck. It passes the network check but instance status check fails, it is showing as Running but I cannot remote to it. It's a RHEL8.4 instance created from AWS AMI RHEL_HA-8.4.0_HVM-20210504-x86_64-2-Hourly2-GP2 (ami-0d81e223398b63904)

It must be a rather random issue because as I said the instance was starting and stopping fine in the previous days but from time to time a glitch happens.

Is this something to do with ENA or NVME or both? Please advise

  • aws ec2 describe-instances --instance-ids i-xxxxxxx --query "Reservations[].Instances[].EnaSupport" comes TRUE

1 Answers


Based on the fact that t2 and t3 instance types use different virtualisation (t2 uses Xen, t3 uses Nitro) I suspect the issue may be the ENA driver.

If you changed the instance type to an instance built on the Nitro System, status checks fail if you migrated from an instance that does not have the required ENA and NVMe drivers. For more information, see However, you mentioned that is was working fine until in the last 2 weeks but it is not the problem that you encounter daily.

For more information on the ENA driver on Red Hat, see [this](How do I install and activate the latest ENA driver for enhanced network support on an Amazon EC2 instance running Red Hat 6/7?) on how to install and activate the latest ENA driver.

The following documents will help you to troubleshoot the instance status check fails. [1] [2]

I hope the above information is helpful. Kindly let me know if you have additional concerns.

Thank you.

answered 15 days ago

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