The following step instructs the user to upgrade a fabric child container, however the actual result of the command will upgrade both the root container and the childOfRoot containers:

Upgrade the root container last (that is, the container that you originally installed the patch on) and its children (if any). For example, if the root container has a single child container, childOfRoot, enter:
fabric:container-upgrade 1.1 root childOfRoot

The fabric:container-upgrade command usage is as follows:

JBossFuse:karaf@root> fabric:container-upgrade --help
DESCRIPTION
fabric:container-upgrade

Upgrade containers to a new version

SYNTAX
fabric:container-upgrade [options] version [container]

ARGUMENTS
version
The version to upgrade to.
container
The list of containers to upgrade. An empty list implies the current container.

OPTIONS
--all
Upgrade all containers
--help
Display this help message