Storage is one of the most important infrastructure decisions because the requirements are driven by both the amount of data and the way applications and users need to access it.
Start with the storage requirement
Before comparing products, establish how much data needs to be stored, how quickly it needs to be accessed, how many systems need access to it and what level of availability and protection is required.
NAS, SAN and DAS
| Technology | Basic approach | Typical consideration |
|---|---|---|
| NAS | Network-attached storage | Useful where files and shared data need to be accessed over a network. |
| SAN | Storage presented to servers through a dedicated storage network | Often considered where storage performance, centralisation and server connectivity are important. |
| DAS | Storage directly attached to a system | Useful where storage is associated directly with a server or host. |
Hard drives and SSDs
Drive choice involves a balance between capacity, performance, endurance, compatibility and cost. Server and NAS environments can have different requirements from desktop storage, so the intended platform matters.
RAID and redundancy
RAID can be used to organise multiple drives and provide different combinations of capacity, performance and redundancy. The correct RAID level depends on the workload and the consequences of drive failure. RAID should not be treated as a replacement for a separate backup strategy.
Storage accessories and components
Storage infrastructure can include RAID controllers, drive carriers, cables, enclosures and other components. Compatibility with the host system is an important part of selection.
Questions to answer before buying
- How much usable capacity is required?
- How quickly must data be accessed?
- How many users or systems will access the storage?
- Is centralised storage required?
- Is redundancy required?
- How will the data be backed up?
- What capacity growth is expected?
- Are the drives and components compatible with the intended system?
Capacity alone does not describe a storage solution. Access, performance, redundancy, backup and growth all need to be considered.