Comment 3 for bug 1036902

Reviewed: https://review.openstack.org/11375
Committed: http://github.com/openstack/nova/commit/9fffd28cee6669089159047b2bbb5e0539ab4299
Submitter: Jenkins
Branch: master

commit 9fffd28cee6669089159047b2bbb5e0539ab4299
Author: Rafi Khardalian <email address hidden>
Date: Tue Aug 14 13:42:22 2012 +0000

    Restore libvirt block storage connections on reboot.

    Fixes bug 1036902.

    There are a number of cases where block storage connections are not
    properly restored, impacting libvirt in particular. The most common
    case is a VM which has block storage attached via iSCSI, whereby the
    physical system is rebooted. When the system comes back up and
    starts nova-compute, the iSCSI connections are NOT recreated for the
    instances slated to be resumed (assuming
    resume_guests_state_on_host_boot is set).

    The patch changes the compute manager to pass block_storage_info via
    driver.reboot() and driver.resume_state_on_host_boot(). The fix is
    actually only present in the libvirt driver. However, all the other
    drivers were updated to accept the additional, optional function
    arg.

    With the changes in place, iSCSI connections for libvirt are
    re-established after a hypervisor reboot with
    resume_guests_state_on_host_boot=True and on every hard_reboot.
    The latter is intended so that users have a last ditch option for
    recovering their VMs without administrative involvement.

    Change-Id: Idf5d53f21991a359bec6ce26ae9fe3bd61800ce3