Let's take a look at the jargon used and how they can help solve the above issues, mainly on over-provisioning (that lead to high costs) & availability/DR related issues.
- RAID: Some said RAID is the earliest form of storage virtualization, as a logical volume can span across multiple disks to prevent single disk failure.
- I/O Multipathing (MPIO): In the event that one or more of these components fails, causing the path to fail, multipathing logic uses an alternate path for I/O so that the servers & applications can still access their data.
- Remote synchronization: To eliminate storage as single point of failure, data across two separately located storage are replicated over the network on a per volume basis. It presents a single logical volume to the servers, although it may span across different storage boxes. It is also essential to implement multi-site failover clustering for Windows 2008 servers.
- Thin provisioning: It is easier and less troublesome to extend a volume rather than shrinking it. Hence, most administrators tend to over-provision storage space for applications. To reduce wastage, thin provisioning allows administrators to provision a large volume but only a small fraction is actually allocated until the applications occupy more space over time.
- Thin replication: You replicate a "thinly" provisioned volume. Only delta changes will be replicated across and save network bandwidth.
- Point in time Snapshot: To simplify data restoration & DR recovery, periodic snapshots on the storage are taken over time. It allows you to rollback data to certain points in time.
- Deduplication: When you implement server virtualization or VDI, most of the bits and bytes of the VHDs are identical. Deduplication further optimizes storage space by removing duplicated bits & bytes.