Gary,

I hope you are doing well. I was trying to understand the logic in this code when using datastore_regex. It seems even if  you set that parameter and it matches some N datastores, the "free capacity " being returned by nova-compute is only from a single/best datastore.

def get_available_datastores(session, cluster=None, datastore_regex=None):     """Get the datastore list and choose the first local storage."""     ds = session._call_method(vutil,                               "get_object_property",                               cluster,                               "datastore")

... ...

if _is_datastore_valid(propdict, datastore_regex, allowed_ds_types):             new_ds = ds_obj.Datastore(                     ref=obj_content.obj,                     name=propdict['summary.name'],                     capacity=propdict['summary.capacity'],                     freespace=propdict['summary.freeSpace'])             # favor datastores with more free space             if (best_match is None or                 new_ds.freespace > best_match.freespace):                 best_match = new_ds

return best_match

The issue we are seeing is a customer has for example 5 x 10 GB data stores (DS1,..DS5.)  For whatever reason , DS1 was filled more fully and once it hit close to 100% no new instances could launch as the were blocked by the Nova DiskFilter. I know we can use the disk_allocation to "fool" this but why is not using to total cumulative storage as opposed to the one with most free or first one. I am wondering if there is some configuration issue. If it is supposed to use best_match, should that dynamically change among the matched regex Datastore to the one with most free space? Could it be it is somehow skipping the "best_match" and always using " first local storage"

I appreciate any suggestions or comments you have.

Keith