Delta update support

If you are using Mender Professional or Mender Enterprise, you have access to robust delta updates. In this section we describe how to enable support for delta updates on your devices, by installing the mender-binary-delta Update Module with your Yocto Project build.

Once your devices support installing delta updates, see Create a Delta update Artifact for a tutorial on how to create a delta update from two Operating System updates.

Prerequisites

In order to use delta update, you must be using a read-only root filesystem. For details on how to enable this, see the Read only root filesystem section.

Download mender-binary-delta

If you are using hosted Mender, download the mender-binary-delta archive with the following command:

HOSTED_MENDER_EMAIL="myusername@example.com"
curl -u $HOSTED_MENDER_EMAIL -O https://downloads.customer.mender.io/content/hosted/mender-binary-delta/1.4.1/mender-binary-delta-1.4.1.tar.xz

Replace the value of HOSTED_MENDER_EMAIL with the email address you used to sign up on hosted Mender, then enter your hosted Mender password when prompted to proceed. NOTE: if you signed up using your Google or GitHub login, use the email address linked to that account and enter x as the password.

On the other hand, if you are using on-premise Mender Enterprise, download using the following command:

MENDER_ENTERPRISE_USER=<your.user>
curl -u $MENDER_ENTERPRISE_USER -O https://downloads.customer.mender.io/content/on-prem/mender-binary-delta/1.4.1/mender-binary-delta-1.4.1.tar.xz

Unpack mender-binary-delta-generator

The archive mender-binary-delta-1.4.1.tar.xz contains the binaries needed to generate and apply deltas.

Change directory to $HOME:

cd ${HOME}

Unpack the mender-binary-delta-1.4.1.tar.xz in your home directory:

tar xvf mender-binary-delta-1.4.1.tar.xz

We only need the generator, so copy it to /usr/bin:

sudo cp mender-binary-delta-1.4.1/x86_64/mender-binary-delta-generator /usr/bin

Then delete the rest of the unpacked files:

rm -rf mender-binary-delta-1.4.1

Integrate mender-binary-delta into the Yocto environment

Add meta-mender-commerical layer to your Yocto environment:

bitbake-layers add-layer ../sources/meta-mender/meta-mender-commercial

Add the following your local.conf to include mender-binary-delta in your build:

cat <<EOF >> conf/local.conf
# Customizations for Mender delta-update support

IMAGE_INSTALL:append = " mender-binary-delta"
LICENSE_FLAGS_ACCEPTED:append = " commercial_mender-yocto-layer-license"
SRC_URI:pn-mender-binary-delta = "file://${HOME}/mender-binary-delta-1.4.1.tar.xz"

EOF

Next steps

For information on how to create delta update Artifacts, see Create a Delta update Artifact.

For more information about delta updates, including how to deploy them, as well as troubleshooting, see the Mender Hub page about mender-binary-delta.