The cost to acquire and manage highly available and reliable storage can represent a significant part of information technology budgets. Windows Server 2012 addresses this issue by delivering a sophisticated virtualized storage feature called Storage Spaces as part of the Windows Server 2012 storage platform. This provides an alternative option for companies that require advanced storage capabilities at a lower price point.
Storage Spaces introduces a new class of sophisticated storage virtualization innovations and the entire stack has been fundamentally enhanced to incorporate a number of new capabilities that include the following:
- Storage pools. Storage pools are the fundamental building blocks for Storage Spaces. IT admins can flexibly create storage pools based on the needs of the deployment.
- For example, given a set of physical disks, an admin can create one pool (using all the available physical disks) or multiple pools (by dividing the physical disks as required). To maximize the value from storage hardware perspective, the admin can map a storage pool to combinations of hard disks (HDDs) as well as solid-state drives (SSDs). Pools can be expanded dynamically by simply adding additional drives, thereby seamlessly scaling to cope with unrelenting data growth.
- Enterprise Clustering. Storage Spaces includes a failover clustering platform to achieve High Availability (HA) clustered storage. Storage Spaces supports SAS and SATA interfaces. However, only SAS is considered enterprise-grade qualitywith dual paths to connect to, as opposed to just one for SATA.
NOTE: -- For clustered Storage Spaces the hard drive (HDD) or solid state drive (SSD) MUST be SAS. Storage Spaces does not support iSCSI and Fibre Channel external storage.
- Resilient storage. Storage Spaces support two optional resiliency modes: mirroring and parity. Per-pool support for disks that are reserved for replacing failed disks (hot spares), background scrubbing, and intelligent error correction 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.
- Storage Spaces RAID. Windows Server 2012 offers simple spaces, mirror spaces, and parity spaces, each with unique characteristics.
- Simple Spaces: Designed for increased performance without increased resiliency. They are best suited for temporary data, such as video rendering files, image editor scratch files, and intermediary compiler object files.
- Mirror Spaces: Designed for increased performance and increased resiliency. They are well suited to storing a broad range of data, from a general-purpose file share to a VHD library. When a mirror space is formatted with the Resilient File System (ReFS), Windows offers automatic data integrity maintenance. This is a layer of resiliency is above and beyond the resiliency achieved from maintaining multiple data copies to tolerate drive failure.
- All storage spaces in the storage pool must use fixed provisioning.
- Two-way mirror spaces must use three or more physical disks
- Three-way mirror spaces must use five or more physical disks
- Parity spaces are not supported
- All physical disks in a clustered pool must be connected via SAS
- All physical disks must support persistent reservations and pass the failover cluster validation tests
- Parity Spaces: Designed for capacity efficiency and increased resiliency. Parity spaces are best suited for archival data and streaming media, such as music and videos.
- 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.
- Multi-tenancy. 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 and can be fully integrated with Active Directory Domain Services.
- Optimal storage use. Server consolidation often results in multiple data sets sharing the same storage hardware. Storage Spaces supports thin provisioning to allow businesses to easily share storage capacity among multiple unrelated data sets and thereby maximize capacity use.
- Storage Spaces also supports trim, automatically running the Storage Optimizer to help reduce the physical footprint of data by consolidating data.
- Operational simplicity. Fully remoteable and scriptable management is permitted through the Windows Storage Management API, WMI, and Windows PowerShell. Storage Spaces can 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.