datastore selection is incorrect if token is being used

[Radoslav Gerganov]

If the number of datastores is greater than the maximum, the PropertyCollector returns a token value that should be used to iterate over the entire result set. The get_datastore_ref_and_name function in vm_util.py is aware of tokens but it stops on the first found datastore (line 942) instead searching for the best match over the entire set.

We should improve get_datastore_ref_and_name to:
1) clearly specify how the datastore is selected (the current pydoc is wrong)
2) select the best match by iterating the whole result set

[Shawn Hartsock (hartsock)]

We should break each of these points into separate bugs (since you can list them independently). Hopefully that will make the changes smaller, easier to digest, and faster to get approved.

[Radoslav Gerganov (rgerganov)]

The pydoc change is really trivial and I thought it will be fine to fix both problems with one patch. If you believe this is not the case (I am still getting started with the dev process here), then I will split it. Thanks!

[Shawn Hartsock (hartsock)]

In the case of patches, the smaller the patch the more probable it is to be accepted. That's just a function of having fewer points to object to. You could have a perfectly valid patch fixing two problems held up because of a discussion related to only one of the solutions... and the result could be that neither problem gets fixed. So it's in everyone's best interest to deal with smaller patches that do one thing at a time.

[dan wendlandt (danwent)]

https://review.openstack.org/#/c/54361/

Looks like jenkins missed the tag on this one.

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/54361
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=b7bf623d79608df8ff5bf8040dc3590da7eeb236
Submitter: Jenkins
Branch: master

commit b7bf623d79608df8ff5bf8040dc3590da7eeb236
Author: Radoslav Gerganov <email address hidden>
Date: Tue Oct 29 17:41:52 2013 +0200

    VMware: fix datastore selection when token is returned

    Use the token returned by the PropertyCollector to iterate
    over the complete set of datastores and select the best
    match based on the regular expression and the free space on
    the datastore.

    Closes-Bug: #1245564
    Change-Id: If24c37a41bfa994a990aaa4a3e21d16b33aad42f