Status and Power States of Instances on EO-Lab
In OpenStack, instances have their own Status and Power State:
Status informs about the present condition of the VM, while
Power States tell us only whether virtual machines are running or not.
There are six Power States, divided into two groups, depending on whether VM is running or not.
NO STATE - VM is running, but encountered fatal errors that may require debugging
RUNNING - VM is running fine
PAUSED - VM is frozen and a memory dump is made
While turned off:
SHUT DOWN - VM is powered off properly
CRASHED - VM is turned off due to a fatal error
SUSPENDED - VM is blocked by the system
Status and its Conditions
Status may have one of the following conditions:
ERROR – instance is not working due to problems in creation process
ACTIVE – instance is running with the specified image
PAUSED – instance is paused with the specified image
SUSPENDED – instance is suspended with the specified image, with a valid memory snapshot
SHUT OFF – instance is powered down by the user and the image is on disk
SHELVED OFFLOADED – instance is removed from the host and it can be reactivated using the Unshelve instance button
RESIZED/MIGRATED - instance is stopped on the source node but running on the destination node. Images exist at two locations. User intervention is required.