physical-sector · shipping · also physical block (storage)

Physical sector

A physical sector is the device-level data unit whose reported size describes physical read/write granularity rather than logical addressing.

Treat the reported value as information at a particular storage layer, not a measurement of hidden flash geometry. Do not infer application-level power-loss behavior from this field alone.

Relations

related

logical-sector, advanced-format, 512e, 4kn-native, partition-alignment, power-loss-protection, torn-write, rwf-atomic

Advantages

• Helps callers choose requests that cover complete physical sectors. [2]

Limitations

• Linux can synthesize the reported physical block size from component devices in a stacked configuration. [1]
• Torn-write protection requires a separately supported atomic-write contract. [3]

Citations

1. Linux 6.12: stable sysfs block ABI, sector sizes and I/O topology (accessed 2026-10-12)
2. Microsoft: File buffering, alignment and file access requirements (accessed 2026-10-12)
3. Linux ext4 documentation: Atomic Block Writes, requirements and semantics (accessed 2026-10-12)
4. Hesela: 512e, 4Kn and alignment: geometry is not durability (accessed 2026-10-12)

JSON: /data/terms/physical-sector.json