Since Openstack is based on a shared filesystem backend, we need to divide the storage in to specific chunks or “Pools” based on the tasks we need these in order to accomplish said task.
VMS (Virtual Machine’S’):
Used to create ephemeral disks for instances to use. Anything in the VMS pools gets deleted once the instance connected to it is deleted.
Images:
Mostly used for operating systems used to create instances.
Volumes:
Persistent Data disks. Disks in this pool will only be deleted if specifically told to do so by the operator. Warning: See Delete Volume on instance deleted: