(ii) Can I deploy separately SAN storage after overcloud deployment, I mean after a month of openstack deployment i want to add SAN storage to my infrastructure. Is it possible?
The short answer is yes. TripleO has the ability to deploy additional cinder storage backends via what's known as a stack (i.e. the overcloud) update. The initial overcloud deployment can be done using another cinder backend X, and later you can add a Huawei backend so the overcloud has two backends (X + Huawei).
(iii)
Please advise me how to deploy Huawei oceanstor SAN storage.
TripleO does not have specific support for deploying a Huawei SAN, but you can still deploy one by following [2]. That doc describes the technique for how to deploy the Huawei SAN as a "custom" block storage device. The document provides an example for deploying two NetApp backends, but the concept will be the same for you to deploy a single Huawei backend. The key will be crafting the TripleO environment file to configure the Huawei settings described in [1].
One additional thing to note is that I see the Huawei driver requires access to an XML file that contains additional configuration settings. You'll need to get this file onto the overcloud node(s) where the cinder-volume service runs. And if your overcloud services run in containers (as modern TripleO releases do), then you'll need to provide a way for the containerized cinder-volume service to have access to the XML file. Fortunately this can be achieved using a TripleO parameter by including something like this in one of the overcloud deployment's env file:
parameter_defaults:
CinderVolumeOptVolumes:
- /etc/cinder/cinder_huawei_conf.xml:/etc/cinder/cinder_huawei_conf.xml:ro
That will allow the /etc/cinder/cinder_huawei_conf.xml file installed on the overcloud host to be visible to the cinder-volume service running inside a container.
Alan
Please advise further. Thank you