IT KORR Knowledge Center
Storage Planning Guide
A guide for matching storage architecture to workload, planning capacity and performance, and applying appropriate redundancy.
Workload-to-Architecture Matching
The right storage architecture depends on how the workload accesses data, not on what is already sitting in the data center. Choosing the wrong architecture for a workload creates performance problems that no amount of tuning fully resolves.
- Block storage (SAN) — best for workloads requiring low-latency, high-performance direct disk access: databases, virtualization hosts, transactional applications.
- File storage (NAS) — best for shared file access across many users or systems: home directories, department shares, general-purpose file serving.
- Object storage — best for large volumes of unstructured data accessed less frequently or via application APIs: backups, archives, media, application data at scale.
- A single environment often needs more than one architecture — match each workload individually rather than standardizing on one platform for everything.
Capacity Planning Methodology
- Establish current usage as a baseline, broken out by workload or department where possible.
- Project growth rate using historical trend data, not a flat guess — review at least 6-12 months of usage history where available.
- Set a headroom target (commonly 20-30% free capacity) that triggers a planned expansion before storage runs critically low.
- Re-forecast on a regular cadence (e.g., quarterly) since growth rate can change with new projects or acquisitions.
Performance Requirements
- Identify IOPS and latency requirements per workload — a transactional database has very different needs than an archive.
- Distinguish between random I/O (typical of databases and VMs) and sequential I/O (typical of backups and large file transfers) when sizing storage.
- Match media type to requirement: NVMe/SSD tiers for latency-sensitive workloads, higher-capacity spinning disk for bulk, less latency-sensitive data.
- Validate performance under realistic concurrent load, not just vendor benchmark figures.
Redundancy & RAID Considerations
- Choose a RAID level (or equivalent erasure coding) based on the balance of usable capacity, performance, and failure tolerance the workload needs.
- Account for rebuild time and risk of a second failure during rebuild on larger, higher-capacity drives.
- Redundancy within an array is not a backup — maintain a separate backup strategy regardless of RAID/redundancy level.
- Plan for hot spares or rapid replacement parts to minimize the window of reduced redundancy after a drive failure.
Related Resources
- Storage Architecture: SAN, NAS, and Object — /knowledge-center/infrastructure/infrastructure-networking/storage-architecture-san-nas-object
- Virtualization Fundamentals — /knowledge-center/infrastructure/infrastructure-networking/virtualization-fundamentals