How to Create a RAID Array on Your Synology NAS

A Synology NAS can combine several hard drives into a storage pool that improves capacity, availability, or both. The process is managed through DiskStation Manager (DSM), Synology’s web-based operating system, and usually involves selecting a RAID type, creating a storage pool, and formatting a volume.

RAID is useful for home offices, photographers, and small businesses in Sydney, Melbourne, Brisbane, and beyond. However, it is not a substitute for backups. A failed drive may be replaceable without losing access to files, but accidental deletion, malware, theft, fire, or a corrupted array can still destroy data.

Understand RAID and SHR

Traditional RAID levels use fixed rules for combining disks. RAID 1 mirrors data across two drives, while RAID 5 distributes data and parity across at least three drives. RAID 6 requires four or more drives and can tolerate two drive failures. RAID 10 combines mirroring and striping for strong performance and redundancy.

Synology Hybrid RAID, commonly called SHR, is often the most practical choice for households and small Australian businesses. SHR can use drives of different capacities more efficiently than conventional RAID, making it easier to upgrade gradually when drive prices change at local retailers.

Prepare the NAS and Drives

Check that each disk is compatible with your Synology model and intended workload. NAS-rated drives are designed for continuous operation and vibration, while ordinary desktop drives may be less suitable for a multi-disk enclosure. Keep the drives in their original order until DSM identifies them clearly.

Before creating the storage pool, prepare these items:

Also check the practical setup around the enclosure:

This matters in warmer areas such as Perth or inland New South Wales, where poor airflow can increase drive temperatures. A UPS is also worthwhile if local power interruptions are common.

Choose the Right RAID Level

The ideal configuration depends on the number of bays, drive sizes, required resilience, and available budget. A two-bay NAS generally suits RAID 1 or SHR, while a four-bay model offers more flexible options.

Configuration Minimum drives Drive failure tolerance Practical use
SHR or RAID 1 2 1 Home files and small offices
RAID 5 or SHR-2 equivalent 3 1 Larger shared storage
RAID 6 or SHR-2 4 2 Important business data
RAID 10 4 Usually 1 per mirror High input/output workloads

RAID 5 and RAID 6 sacrifice usable capacity for parity. RAID 10 usually costs more in capacity but can provide better performance for virtual machines or busy databases. Use Synology’s storage calculator before buying disks, and remember that manufacturers advertise decimal terabytes while DSM may display a smaller usable figure.

Create the Storage Pool in DSM

Sign in to DSM, open Storage Manager, and select Storage or Storage Pool, depending on the DSM version. Choose Create, select the available drives, and pick the preferred RAID type. DSM will show estimated capacity and warnings before applying the configuration.

After the storage pool is created, make a volume on it using the recommended Btrfs file system where supported. Btrfs enables features such as snapshots, file self-healing in suitable configurations, and more flexible protection against certain forms of corruption. Enable data scrubbing later, rather than interrupting initial setup.

The first synchronisation can take many hours or longer, especially with large disks. You can often use the NAS during this period, but performance may be reduced. Avoid unplugging the unit or forcing a restart while DSM is building the array.

Expand and Replace Drives Safely

When a disk reports errors, open Storage Manager and review its health details before removing anything. Replace only the failed drive, and choose a disk that is at least as large as the smallest member of the array. A replacement with a slightly smaller real capacity may be rejected even when its advertised size appears equal.

Many Synology models support expanding an SHR pool by adding drives or replacing existing disks with larger ones. Expansion happens in stages: replace one disk, repair the pool, wait for the repair to finish, and then continue. This gradual approach is safer than removing several disks at once.

Protect Files Beyond RAID

Use Hyper Backup, Snapshot Replication, or another backup system to maintain separate copies. A sensible small-business arrangement may include a second NAS, encrypted USB storage, or reputable cloud storage. Keep at least one copy away from the premises, especially where bushfire, flooding, or theft is a concern.

For Australian users, internet upload speeds can vary widely between an NBN FTTP connection in Melbourne and a slower regional service. Schedule cloud backups overnight and prioritise irreplaceable files first. If your work involves German tax records or overseas administration, keep relevant documents organised and consider specialist resources such as German tax guidance alongside your normal backup routine.

Monitor Health and Plan Recovery

Enable DSM notifications for degraded pools, high temperatures, failed sectors, and low storage capacity. Run periodic S.M.A.R.T. tests and data scrubbing, but schedule them outside busy work periods. Review backup logs as well; a backup that silently fails provides false confidence.

Synology’s support documentation, hardware compatibility list, and network storage resources can help when choosing drives or troubleshooting a storage pool. Keep replacement hardware and a written recovery procedure available if the NAS supports business operations.

A RAID array improves availability, but it cannot prevent every form of data loss. The key points are to select a suitable RAID or SHR layout, allow repairs to finish, monitor drive health, and maintain independent backups. A well-managed Synology NAS should make storage more resilient without pretending that redundancy is the same as protection.