LeftHand AO volume create performance improvement

[Jim Branen]

With respect to the StoreVirtual OS, it has come to our attention that setting some of the volume creation properties may slow down the operation significantly, specifically AdaptiveOptimization (AO). AO defaults to ‘true’ if you don’t specify the value on a create, and that is the most efficient way to create a volume. If you pass in “false” or “true” for AO, it will result in an update operation following the create operation to set this value, so it is best to not specify the value and let it default to “true”. There are really no disadvantages to doing this. If the SAN would actually have tiered storage and the volume was residing on the tiered storage, then the flag would allow the volume to auto-tier, otherwise it means nothing.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/78055

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/78055
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=52a7d601a0c97ab4eb47b9bf10da19a9f61afe25
Submitter: Jenkins
Branch: master

commit 52a7d601a0c97ab4eb47b9bf10da19a9f61afe25
Author: Jim Branen <email address hidden>
Date: Tue Mar 4 16:38:41 2014 -0800

    Fix HP LeftHand Performance issue with AO

    Setting AdaptiveOptimization (AO) to ‘true’, the default value,
    at volume create time significantly slows down the operation on
    the LeftHand array. If at create time, AO is set to ‘true’, it
    will result in an update operation following the create operation
    to set this value. Therefore, it is best to not specify the value,
    when ‘true’, and let it default to ‘true’.

    Change-Id: I2c8860e3f25a7bcaa2d2efefeffc1c11319f33e2
    Closes-Bug:#1285925