Build an ISO Hybrid Live Image

A Live ISO image is a system on a removable media, e.g CD/DVD or USB stick. Once built and deployed it boots off from this media without interfering with other system storage components making it a useful pocket system for testing and demo- and debugging-purposes.

To add a live ISO build to your appliance, create a type element with image set to iso in your config.xml (see Build Types) as shown below:

<image schemaversion="6.9" name="JeOS-Tumbleweed">
  <!-- snip -->
    <type image="iso" primary="true" flags="overlay" hybridpersistent_filesystem="ext4" hybridpersistent="true"/>
    <!-- additional preferences -->
  <!-- snip -->

The following attributes of the type element are relevant when building live ISO images:

  • flags: Specifies the live ISO technology and dracut module to use, can be set to overlay or to dmsquash.

    If set to overlay, the kiwi-live dracut module will be used to support a live ISO system based on squashfs and overlayfs. If set to dmsquash, the dracut standard dmsquash-live module will be used to support a live ISO system based on squashfs and the device mapper. Note, both modules support a different set of live features.

  • hybridpersistent: Accepts true or false, if set to true then the resulting image will be created with a COW file to keep data persistent over a reboot

  • hybridpersistent_filesystem: The filesystem used for the COW file. Possible values are ext4 or xfs, with ext4 being the default.

With the appropriate settings present in config.xml KIWI can now build the image:

$ sudo kiwi-ng --type iso system build \
      --description kiwi-descriptions/suse/x86_64/suse-leap-15.1-JeOS \
      --target-dir /tmp/myimage

The resulting image is saved in the folder /tmp/myimage and can be tested with QEMU:

$ qemu -cdrom LimeJeOS-Leap-15.1.x86_64-1.15.1.iso -m 4096

The image is now complete and ready to use. See Deploy ISO Image on an USB Stick and Deploy ISO Image as File on a FAT32 Formated USB Stick for further information concerning deployment.