Samsung has announced the launch of an industry-standard key-value SSD prototype

     Samsung has introduced a key-value SSD prototype to be compatible with this industry standard for key storage devices. Most hard drives and SSDS expose their storage capacity through a block storage interface, where the drive stores blocks of a fixed size (typically 512 bytes or 4KB), and they are identified by logical block addresses that are typically 48 or 64 bits.

     Key-value drives extend this model so that drives can support variable-size numeric values instead of fixed-size LBA, and variable-size values instead of fixed 512B or 4kB blocks. This allows key-value drives to be used more or less as an alternative to a key-value database for software such as RocksDB, as well as as a back end for building applications on a key-value database.

     When used to replace a software-based key-value database, key-value SSDS have the potential to offload significant workloads from the server CPU. What's more, moving the key-value interface to the SSD itself means it can be tightly integrated with the SSD's flash conversion layer, reducing the overhead of emulating block storage devices and layering variable-size storage systems. This means that key-value SSDS can operate at lower write magnifying rates and higher performance than software key-value databases, with only one layer of discarded data in the stack that needs to be collected, rather than one layer in the SSD and one layer in the database.

     Samsung has been working on key-value SSDS, and they have been developing open source software to support key-value SSDS, including the basic libraries and drivers needed to access key-value SSDS as well as sample benchmarking tools and Ceph backend. The Samsung Platform Development Kit software for key-value SSDS initially supported only Samsung's own software apis, but starting today also supports the vendor-neutral SNIA standard API, which is an advanced transport-independent API that can use NVMe, SAS or SATA interfaces.