Back to: Storage Area Network (SAN) Storage
A Storage Pool is a collection of physical disks grouped together to create and manage storage resources efficiently. Storage is provisioned from these pools or RAID arrays, and they are used to create Logical Unit Numbers (LUNs), Consistency Groups, File Systems, and VMware Datastores.
Purpose of Storage Pools
Storage pools provide optimized storage for a particular set of applications or conditions. The configuration of a storage pool defines the types and capacities of the disks in the pool. Users can define RAID configurations, including RAID types and stripe widths, when selecting a tier to build a storage pool.
Components of Storage Pools
- Physical Disks: The building blocks of storage pools.
- RAID Configuration: Determines data redundancy and performance.
- Tiers of Storage: Pools can contain different performance tiers (e.g., SSD, SAS, NL-SAS).
- Storage Allocation: Used to create LUNs, file systems, and datastores.
RAID Configurations in Storage Pools
RAID (Redundant Array of Independent Disks) enhances performance, redundancy, and availability. The commonly used RAID levels include:
- RAID 0 (Striping): Offers high performance but no redundancy.
- RAID 1 (Mirroring): Provides high redundancy with one-to-one disk mirroring.
- RAID 5 (Striping with Parity): Balances performance and redundancy, requiring a minimum of three disks.
- RAID 6 (Dual Parity): Enhanced fault tolerance, allowing two disk failures.
- RAID 10 (Mirroring + Striping): Combines performance and redundancy but requires a minimum of four disks.
Storage Provisioning: Thin and Thick
Storage provisioning refers to the allocation of storage resources to applications or users. It is categorized into two types:
- Thin Provisioning:
- Allocates storage on demand, optimizing space utilization.
- Reduces wasted storage by allocating only what is needed.
- Ideal for dynamic workloads with varying storage needs.
- Thick Provisioning:
- Allocates the entire storage capacity upfront.
- Ensures consistent performance by reserving dedicated space.
- Suitable for applications with predictable storage demands.
Best Practices for Storage Pool Configuration
- Select the Right RAID Level: Choose a RAID level based on performance, redundancy, and application needs.
- Use Storage Tiering: Combine SSD, SAS, and NL-SAS to optimize cost and performance.
- Monitor and Balance Workloads: Prevent performance bottlenecks by monitoring disk utilization.
- Ensure Sufficient Spare Disks: Maintain hot spares to reduce downtime in case of disk failures.
- Align with Application Needs: Match storage configurations to the specific performance and availability needs of applications.
Conclusion
Storage pools and RAID configurations play a crucial role in optimizing storage performance, capacity, and redundancy. Proper selection and management of storage pools ensure high availability, fault tolerance, and efficient data management in enterprise environments.