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.

../_images/statuspower.png

There are six Power States, divided into two groups, depending on whether VM is running or not.

Power States

While running:

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.