Introduction
Here you can find basic information about CloudStack and the StorPool plugin. For a high-level overview on how you can accelerate your CloudStack deployment using StorPool see the StorPool site.
Plugin overview
As described in About Primary Storage, CloudStack is designed to work with many standards-compliant storage systems. The choice of systems is based on the selected hypervisor. StorPool Storage is supported by the KVM hypervisor, and can be used as a Zone-wide primary storage.
The StorPool plugin is deeply integrated with CloudStack. When used with service or disk offerings, an administrator is able to build an environment in which a root or data disk that a user creates leads to the dynamic creation of a StorPool volume, which has guaranteed performance. Such a StorPool volume is associated with one CloudStack volume, so performance of the CloudStack volume does not vary depending on how heavily other tenants are using the system. The volume migration is supported across non-managed storage pools (for example, local storage) to StorPool, and across StorPool storage pools.
Cloudstack overview
Primary and Secondary storage
Primary storage is associated with a cluster or zone, and it stores the virtual disks for all the VMs running on hosts in that cluster/zone.
Secondary storage includes the following:
Templates are OS images that can be used to boot VMs, and can include additional configuration information, such as installed applications.
ISO images are disc images containing data or bootable media for operating systems.
Disk volume snapshots are saved copies of VM data, which can be used for data recovery or for creating new templates.
ROOT and DATA volumes
ROOT volumes correspond to the boot disk of a VM. They are created automatically by CloudStack during VM creation. These volumes are created based on a system disk offering, corresponding to the service offering the user VM is based on. We may change the ROOT volume disk offering but only to another system created disk offering.
DATA volumes correspond to additional disks. These can be created by users and then attached or detached to VMs. DATA volumes are created based on a user-defined disk offering.