Comment 14 for bug 1543233

Reviewed: https://review.openstack.org/278492
Committed: https://git.openstack.org/cgit/openstack/fuel-agent/commit/?id=4c74eaa1875dd28d2e2c8256281d9088f83f25fb
Submitter: Jenkins
Branch: master

commit 4c74eaa1875dd28d2e2c8256281d9088f83f25fb
Author: Alexander Gordeev <email address hidden>
Date: Wed Feb 10 19:07:48 2016 +0300

    Switch from optimal alignment to minimum

    fuel-agent always uses optimal alignment for partitions and
    thoroughly relies on parted to perform that aligning. (-a optimal)

    The issue is that under certain circumstances due to that alignment,
    the end of particular partition could cross 1M boundary. And due to
    actual partition' bounderies being rounded up, fuel-agent mistakenly
    assumes that partition couldn't fit within provided boundaries and
    raises errors.WrongPartitionSchemeError.

    However, some h/w data storages are well known for reporting
    relatively huge optimal IO sizes (16M or even bigger), so the 1M room
    can't be enough. Thus, optimal aligning is not an option. Therefore,
    parted has been switched to the minimum alignment.

    The min value is the minimum aligment needed to align the partition
    properly to physical blocks, which avoids performance degradation.

    Change-Id: I83116ccc9236053a93664c1cf40a3ef0c1a189b7
    Closes-Bug: #1543233