[DOCS] Clarify is_metal is required if using iSCSI

When using a storage backend which depends on the iSCSI protocol, such
as a NetApp or VNX appliance in iSCSI mode, cinder would work only
partially. New volumes could be created, but download to image and
backup routines would not work, and the reason would not be clear from
the logs.

Change-Id: I361e5e85153886a12ca777f83f7aa60c67b6fbe9
This commit is contained in:
Paulo Matias 2016-08-30 20:12:30 -03:00
parent 8bc6f64003
commit d8daff7691
1 changed files with 14 additions and 2 deletions

View File

@ -8,8 +8,20 @@ using the LVM backend.
.. note::
While this is the default for cinder, using the LVM backend results in a
Single Point of Failure. As a result of the volume service being deployed
directly to the host, ``is_metal`` is ``true`` when using LVM.
Single Point of Failure.
The LVM back end needs to run on the host, however most of the other back ends
can be deployed inside a container. If the storage back ends deployed within
your environment are able to run inside containers, then it is recommended to
set ``is_metal: False`` in the ``env.d/cinder.yml`` file.
.. note::
Due to a
`limitation of the container system <https://bugs.launchpad.net/ubuntu/+source/lxc/+bug/1226855>`_,
you must deploy the volume service directly onto the host when using
back ends depending on iSCSI. That is the case, for example, for
storage appliances configured to use the iSCSI protocol.
NFS backend
~~~~~~~~~~~~