NAS Server

Overview

A network-attached storage appliance is a dedicated file server in a compact tower. Four hard drives pool into a fault-tolerant volume that every machine on the network can mount, with NVMe SSDs acting as a fast cache in front of the spinning disks. Hot-swap trays let a failed drive be replaced without powering down.

The unit is a sheet-metal Chassis holding hot-swap trays. The Motherboard runs the operating system, the Drive Backplane connects the drives, four 3.5" Hard Drive units provide bulk capacity, and two NVMe Cache SSD modules cache hot data. A Network Interface Card handles 10-gigabit networking and the Front Status Panel shows status.

How it works

Each drive slides into a tray that mates blindly with the backplane, which carries combined SATA data and power to every bay. The motherboard's SATA Controller IC presents the four disks to the SoC, where storage software stripes them into a RAID set: parity RAID spreads data and redundancy across all drives so one disk can fail without data loss, and the array rebuilds onto a replacement once inserted.

Reads and writes that hit the same files repeatedly are absorbed by the NVMe cache, which holds frequently accessed blocks and absorbs write bursts before flushing them to the slower platters. Network clients reach the volume over the Network Interface Card: its 10 GbE PHY moves data far faster than a single disk, so the cache and the four-drive array together saturate the link. The Front Status Panel OLED and LEDs surface array health, while the dual rear fans and internal PSU keep the drives cool and powered.