Storage Virtualization (SVC)
- Storage virtualization is a technology that makes one set of resources resemble another set of resources, preferably with more desirable characteristics. It is a logical representation of resources that is not constrained by physical limitations and hides part of the complexity. It also adds or integrates new function with existing services and can be nested or applied to multiple layers of a system.
- it is important that virtualization can be implemented at various layers within the I/O stack and this can be between virtualization at the disk layer (block level) and virtualization at the file system layer (file level).SVC version 7.6 splits the block aggregation layer into three sublayers. Block aggregation can be realized within hosts (servers), in the storage network (storage routers and storage controllers), or in storage devices (intelligent disk arrays).
IBM Spectrum Virtualize provides the following benefits:
- Online volume migration while applications are running, which is possibly the greatest single benefit for storage virtualization. This capability enables data to be migrated on and between the underlying storage subsystems without any effect on the servers and applications. In fact, this migration is performed without the knowledge of the servers and applications that it even occurred.
- Simplified storage management by providing a single image for multiple controllers, and a consistent user interface for provisioning heterogeneous storage.
- Enterprise-level Copy Services functions. Performing Copy Services functions within the SVC removes dependencies on the storage subsystems. Therefore, it enables the source and target copies to be on other storage subsystem types.
- Storage usage can be increased by pooling storage across the SAN. System performance is often improved with IBM Spectrum Virtualize and SVC as a result of volume striping across multiple arrays or controllers and the other cache that it provides.