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Michael Kropat
Asked: 2014-04-28 08:43:13 +0800 CST

What are the different Ubuntu Cloud Guest images (-disk1, -root, -uefi1)? [duplicate]

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On the daily build page on cloud-images.ubuntu.com, there are a number of different images published for each architecture, for example:

  • trusty-server-cloudimg-amd64-disk1.img
  • trusty-server-cloudimg-amd64-root.tar.gz
  • trusty-server-cloudimg-amd64-uefi1.img
  • trusty-server-cloudimg-amd64.tar.gz

What is the difference between these different releases?

The best documentation I can find is this wiki page, but it doesn't seem to answer the question.

server

1 Answers

  1. I can't find any official documentation, but this is what I found by poking around:

    {image}.tar.gz

    $ tar tzf trusty-server-cloudimg-amd64.tar.gz
trusty-server-cloudimg-amd64.img
trusty-server-cloudimg-amd64-vmlinuz-generic
trusty-server-cloudimg-amd64-loader
trusty-server-cloudimg-amd64-floppy
README.files

    So it's a tarball with a kernel image, boot loader, and a filesystem image. More details on the filesystem image:

    $ file trusty-server-cloudimg-amd64.img
trusty-server-cloudimg-amd64.img: Linux rev 1.0 ext4 filesystem data (extents) (large files) (huge files)

    You can access the .img contents with:

    mkdir -p /media/trusty-server-cloudimg-amd64
mount -o loop trusty-server-cloudimg-amd64.img /media/trusty-server-cloudimg-amd64

    {image}-disk1.img

    $ file trusty-server-cloudimg-amd64-disk1.img
trusty-server-cloudimg-amd64-disk1.img: Qemu Image, Format: Qcow , Version: 2

    {image}-root.tar.gz

    We make several formats of images available on cloud-images.ubuntu.com. The one relevant to this mail is the -root.tar.gz. This is essentially a tar -cSpzf - / of the contents of /.

    — Scott Moser posting on ubuntu-devel

    The post goes on to state that the kernel and boot loader have been removed, since the primary use of this release is with LXC, where the kernel and boot loader files aren't used.

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