Hello !

We're planning a new cluster without Ceph storage. We will use an iSCSI pureStorage array for all storage except object storage.

PureStorage provide only a cinder driver. So we will need to user boot on volume nova instances.

My question is about glance. PureStorage speak about Image Cache since Liberty:

https://support.purestorage.com/Solutions/OpenStack/z_Legacy_OpenStack_Refer...

But I wonder if using the cinder backend of glance is a better, simpler, transparent option ?

The Image Cache you referenced is not specific to Pure. It is a common Cinder feature that many backend can leverage. You can use both the image cache and cinder as a glance store as well but they are redundant. It is best to pick one or the other. It depends on the images format you are using. For example if you are using QCOW2 as the format the glance cinder backend cannot optimize it, but the image cache can optimize. Simon