Virtual disks created from free space in a storage pool. Storage spaces have such attributes as resiliency level, storage tiers, fixed provisioning, and precise administrative control.

Storage Spaces includes the following features:

Storage pools. Storage pools are the fundamental building blocks for Storage Spaces. Storage administrators are already familiar with this concept, obviating the need to learn a new model. They can flexibly create storage pools based on the needs of the deployment. For example, given a set of physical disks, an administrator can create one pool (by using all the available physical disks) or multiple pools (by dividing the physical disks as required). Furthermore, to maximize the value from storage hardware, the administrator can combine hard disks and solid-state drives (SSDs) in the same pool, using storage tiers to move frequently accessed portions of files to SSD storage, and using write-back caches to buffer small random writes to SSD storage. Pools can be expanded dynamically by simply adding additional drives, thereby seamlessly scaling to cope with unceasing data growth.
Resilient storage. Storage Spaces provides three storage layouts (also known as resiliency types):
- Mirror. Data is duplicated on two or three physical disks, increasing reliability, but reducing capacity. This storage layout requires at least two disks to protect you from a single disk failure, or at least five disks to protect you from two simultaneous disk failures.
- Parity. Data and parity information are striped across physical disks, increasing reliability, but somewhat reducing capacity. This storage layout requires at least three disks to protect you from a single disk failure and at least seven disks to protect you from two disk failures.
- Simple (no resiliency). Data is striped across physical disks, maximizing capacity and increasing throughput, but decreasing reliability. This storage layout requires at least one disk and does not protect you from a disk failure.
Additionally, Storage Spaces can automatically rebuild mirror and parity spaces in which a disk fails by using dedicated disks that are reserved for replacing failed disks (hot spares), or more rapidly by using spare capacity on other drives in the pool. Storage Spaces also includes background scrubbing and intelligent error correction to allow continuous service availability despite storage component failures. In the event of a power failure or cluster failover, the integrity of data is preserved so that recovery happens quickly and does not result in data loss.
Continuous availability. Storage Spaces is fully integrated with failover clustering, which allows it to deliver continuously available service deployments. One or more pools can be clustered across multiple nodes within a single cluster. Storage spaces can then be instantiated on individual nodes, and the storage will seamlessly fail over to a different node when necessary (in response to failure conditions or due to load balancing). Integration with CSVs permits scale-out access to data.
Storage tiers. Storage Spaces in Windows Server 2012 R2 Preview combines the best attributes of SSDs and hard disk drives (HDDs) by enabling the creation of virtual disks comprised of two tiers of storage – an SSD tier for frequently accessed data, and a HDD tier for less-frequently accessed data. Storage Spaces transparently moves data at a sub-file level between the two tiers based on how frequently data is accessed. As a result, storage tiers can dramatically increase performance for the most used (“hot”) data by moving it to SSD storage, without sacrificing the ability to store large quantities of data on inexpensive HDDs.
Write-back cache. Storage Spaces in Windows Server 2012 R2 Preview supports creating a write-back cache that uses a small amount of space on existing SSDs in the pool to buffer small random writes. Random writes, which often dominate common enterprise workloads, are directed to SSDs and later are written to HDDs.
Operational simplicity. The Windows Storage Management API, WMI, and Windows PowerShell permit full scripting and remote management. Storage Spaces can also be easily managed through the File and Storage Services role in Server Manager. Storage Spaces also provides notifications when the amount of available capacity in a storage pool hits a configurable threshold.
Multitenancy. Administration of storage pools can be controlled through access control lists (ACLs) and delegated on a per-pool basis, thereby supporting hosting scenarios that require tenant isolation. Storage Spaces follows the familiar Windows security model; therefore, it can be fully integrated with Active Directory Domain Services.

	Created by kamsz almost 13 years ago

Microsoft 70-410 Note on Storage spaces, created by kamsz on 19/08/2013.