Understanding VM States

Owned by Alexander Dibbo
Mar 28, 2024
2 min read

Virtual machines (VMs) can exist in various states throughout their lifecycle. It is important to understand these states to best manage your VMs. Below are the different states that a VM can be in:

  • Running - The VM is powered on and running. Whether it is doing anything useful is down to the user

    • Active

    • rescued - the VM will be in a rescue image - used when a VM disk is corrupted

  • Shut down - The VM is powered off but still holds the resources preventing others from using them

    • paused

    • suspended - This state indicates that the VM is suspended, which means that the VM image is saved to disk and the VM is powered off. When the VM is resumed, it is brought back to the state it was in before it was suspended.

    • shutoff

    • stopped

  • Deleted - The resources of the VM are released and the VM no longer exists.

    • deleted

    • soft deleted - This state indicates that the VM is marked for deletion, but the resources are not released yet.

  • Shelved - This state indicates that the VM no longer consumes resources, but the disk and configuration remain so it can be started again later. (Note: This state is not currently supported on the STFC Cloud.)

    • shelved_offloaded

  • Build - the VM is currently being created

    • building

  • Error - This state indicates that there is an issue with either VM creation or an issue during the life of the VM.

    • error

VMs can move between these states for various reasons. It is important to keep track of the state of your VMs and ensure that they are in the appropriate state for their current use case.

 

More explanation on vm states can be found here: https://docs.openstack.org/nova/latest/reference/vm-states.html