This creates a specific slice which all OpenStack services will operate
from. By creating an independent slice these components will be governed
away from the system slice allowing us to better optimise resource
consumption.
See the following for more information on slices:
* https://www.freedesktop.org/software/systemd/man/systemd.slice.html
See for following for more information on resource controls:
* https://www.freedesktop.org/software/systemd/man/systemd.resource-control.html
Tools like ``systemd-cgtop`` and ``systemd-cgls`` will now give us
insight into specific processes, process groups, and resouce consumption
in ways that we've not had access to before. To enable some of this reporting
the accounting options have been added to the [Service] section of the unit
file.
Change-Id: I022ecb7c291287116d184bcedecaf1d39530dd72
Signed-off-by: Kevin Carter <kevin.carter@rackspace.com>