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how to use a disk, kernel and ramdisk from /var/lib/nova/instances

asked 2013-12-11 05:06:27 -0500

bishoy gravatar image

updated 2014-01-22 15:12:50 -0500

Evgeny gravatar image

hi, i want to use or reattach a disk, kernel and ramdsik. this instance was lunched from a qcow image. any help ???

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answered 2013-12-11 09:55:21 -0500

jtopjian gravatar image


qcow images have their kernel and ramdisk contained in the image. As far as I know, there's no way to have qcow images use a kernel and ramdisk specified in another location. If you want to use a different kernel in your instance, you can simply install it inside the instance and reboot.

AMI/AKI/ARI images, on the other hand, need connected together in Glance.

  • AMI is the "disk" portion
  • AKI is the "kernel"
  • ARI is the "ramdisk"

In order to upload these three images into Glance and have them work with each other, you will need to do something like the following:

$ glance image-create --name="my-kernel" --disk-format=aki --container-format=aki < my-kernel
(new uuid will be returned - make note of it)
$ glance image-create --name="my-ramdisk" --disk-format=ari --container-format=ari < my-ramdisk
(new uuid will be returned - make note of it)
$ glance image-create --name="my-linux" --disk-format=ami --container-format=ami \
 kernel_id=<kernel uuid> ramdisk_id=<ramdisk uuid> < my-linux

You can find an example of these three files by downloading "precise-server-cloudimg-amd64.tar.gz" from .

Also, you can find more information on OpenStack and images at the OpenStack Virtual Machine Image Guide:

Hope that helps,


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Asked: 2013-12-11 05:06:27 -0500

Seen: 2,089 times

Last updated: Dec 11 '13