1.3 Chapter Summary
Storage Virtualization Overview
- Storage virtualization depends upon lower layer standards but is not defined by a standards body.
- Storage virtualization provides an abstraction layer over physical storage systems and enables multiple storage assets to be treated as a single logical entity.
- Granular forms of storage virtualization occur in technologies such as RAID.
- The value of storage virtualization is in its ability to automate tedious administrative tasks and reduce costs of storage management.
- The Compaq ENSA initiative leverages storage virtualization for creation of a storage utility.
- Storage virtualization must maintain reliable and transparent access to underlying storage assets.
- Virtualization technology is being driven by all major storage providers.
- Virtualization provides a foundation of logical abstraction upon which more advanced functionality can be built.
- To streamline storage operations, logical abstraction should support automation of routine administrative tasks.
- Automated processes should be policy-based to further reduce manual intervention.
- Logical abstraction, automation, and policy-driven management enable storage virtualization to support application-aware storage management.
- The tight integration of operating systems and virtualization technology will enable applications to more fully leverage virtualized storage.
- Storage virtualization facilitates interoperability of storage systems.
- Virtualization technology can be supported on hosts, networks, or storage arrays and tape subsystems.
- In-band virtualization provides both control and data along the same connection path.
- Out-of-band virtualization separates control and data on different connection paths.
- Not all storage environments require or benefit from virtualization.