【OpenStack】源码级深入了解删除虚拟机操作

ACTIVE = 'active'  # VM is running
BUILDING = 'building'  # VM only exists in DB
PAUSED = 'paused'
SUSPENDED = 'suspended'  # VM is suspended to disk.
STOPPED = 'stopped'  # VM is powered off, the disk image is still there.
RESCUED = 'rescued'  # A rescue image is running with the original VM image
# attached.
RESIZED = 'resized'  # a VM with the new size is active. The user is expected
# to manually confirm or revert.

SOFT_DELETED = 'soft-delete'  # VM is marked as deleted but the disk images are
# still available to restore.
DELETED = 'deleted'  # VM is permanently deleted.

ERROR = 'error'

SHELVED = 'shelved'  # VM is powered off, resources still on hypervisor
SHELVED_OFFLOADED = 'shelved_offloaded'  # VM and associated resources are
# not on hypervisor

ALLOW_SOFT_REBOOT = [ACTIVE]  # states we can soft reboot from
ALLOW_HARD_REBOOT = ALLOW_SOFT_REBOOT + [STOPPED, PAUSED, SUSPENDED, ERROR]
# states we allow hard reboot from

ALLOW_TRIGGER_CRASH_DUMP = [ACTIVE, PAUSED, RESCUED, RESIZED, ERROR]
# states we allow to trigger crash dump

ALLOW_RESOURCE_REMOVAL = [DELETED, SHELVED_OFFLOADED]
# states we allow resources to be freed in

　　在删除虚拟机时，会根据虚拟机状态来进行不同的操作。可以看出deleted和shelved_offloaded两种状态下虚拟机资源完全释放，而shelved