hesela.devUFS WriteBooster
UFS WriteBooster is a host-controlled feature that uses a finite SLC-mode flash buffer to accelerate writes.
KIOXIA describes incoming writes using the user area when the buffer fills, and host-authorized migration there during idle or hibernate periods. This extra movement can increase write amplification. The buffer operates NAND in one-bit mode; it is not a volatile DRAM cache. [1]
Linux v6.12 separates buffer-flush permission from status: wb_flush_status distinguishes idle, ongoing, prematurely stopped, successful and failed operations. Enabling flushing does not establish successful completion. [2]
WriteBooster buffer migration is not the Linux block layer's volatile-cache preflush or per-write FUA completion contract. Treat their different uses of "flush" separately. This is a comparison of documented interfaces, not a device power-loss test. [1] [3]
Relations
- related
- UFS (Universal Flash Storage), SLC cache, Write amplification, Flash translation layer (FTL), Storage cache flush, Force Unit Access
Limitations
- A burst write rate does not establish sustained throughput after buffer exhaustion. [1]
Citations
- KIOXIA: Understanding the WriteBooster Feature, January 2023, Rev. 2.0, pages 1-3
- Linux v6.12: UFS sysfs ABI, WriteBooster controls, attributes and effective capabilities
- Linux v6.12: Explicit volatile write back cache control, REQ_PREFLUSH and REQ_FUA
Further reading
Sources & caveats
- Source review of a dated vendor brief and Linux v6.12, not a JEDEC conformance review, measured throughput result or universal device guarantee.