Kernels, RAM Disks, and Block Device Mappings FAQ

What are user selectable kernels?

Amazon EC2 provides user selectable kernels which enables you to select a kernel when bundling an AMI or launching an instance. User selectable kernels are useful for keeping your instances up to date with security fixes and updates, being able to use functionality provided by new distributions, and for using specialty applications that have unique timing requirements.

How do I find user selectable kernels?

Use the DescribeInstances operation with the --kernel option. This lists all public kernels that are currently available. After locating a kernel to launch or bundle with your AMI, go to the Resource Center and search for it to determine whether there are any known issues and whether it has any dependencies.

Can I use my own kernel?

Not at present. However, as of version 2008-02-01 of the Amazon EC2 API you can use any of the kernels published by Amazon EC2 or selected vendors.

What type of dependencies do kernels have?

Kernels are most likely to require a RAM disk that contains required drivers (e.g., Xen drivers, video drivers, and so on). If you launch a kernel without a required RAM disk, it will not work properly.

How do I know a kernel/AMI combination will work together?

If you are concerned about whether the kernel/image combination will work well together, Amazon provides several AMIs that have tested combinations that you can use as a starting point for your AMIs or AMIs that you can use as a foundations for a public AMIs. If you require a certified kernel/ AMI combination, you can find them as paid AMIs through organizations such as RedHat. For more information, see Paying for AMIs.