Zoned storage is an innovative approach to data management for large-scale infrastructures. It divides the storage device's address space into zones, introducing unique write constraints compared to traditional storage methods.
Zoned storage leverages two key technologies:
- Shingled Magnetic Recording (SMR) in Hard Disk Drives (HDDs): SMR allows for higher data density by partially overlapping data tracks. However, this technique necessitates sequential writes within a zone.
- Zoned Namespaces (ZNS) in Solid State Drives (SSDs): ZNS acts as the SSD counterpart to SMR, enabling zoned storage functionality with similar write constraints.
Write Constraints: Unlike traditional storage, data within a zone cannot be directly overwritten. Each zone maintains a write pointer that tracks the next available space. To overwrite existing data, the entire zone must be erased using a specific command, effectively deleting all information within it. This necessitates writing new data sequentially from the beginning of the zone.
Reading data, however, remains largely unrestricted. Information within a zone can be accessed in the same manner as on traditional storage devices.
Zoned storage emerged as an answer to the zettabyte capacity era. Enterprises managing massive data infrastructures, often utilising tens of thousands of HDDs and SSDs, require efficient storage solutions. Zoned storage offers a novel approach to increase storage capacity without compromising performance.
Industry Collaboration: It's important to note that zoned storage is an open-source initiative driven by multiple companies like Western Digital, aiming to establish a standardised approach for efficient data management in the face of ever-growing data demands.
Figure from Western Digital:
