hesela.devGeckoFTL
GeckoFTL is a research flash translation layer that stores page-validity metadata in flash using a buffered, merge-based structure.
Logarithmic Gecko groups invalid-page bits into sorted runs. Queries combine bitmaps newest-first; an erase flag excludes obsolete history from a previous block lifetime. This exchanges cheaper metadata updates for more expensive collection queries. [1]
An overwrite can miss the old physical address when its mapping is not cached. The 2015 precursor reconciles delayed invalidations through translation-page reads and cached state before moving victim pages. Its Lazy Gecko garbage collector is distinct from LazyFTL. [2]
Relations
- related
- Flash translation layer (FTL), Garbage collection (flash), SSD mapping cache, Reverse mapping (FTL), Write amplification, LazyFTL
Limitations
- Evaluation uses EagleTree simulation, not measurements of shipping SSDs. Metadata-only overhead reductions do not describe all device traffic. [1]
Citations
- Dayan, Bonnet and Idreos. GeckoFTL: Scalable Flash Translation Techniques For Very Large Flash Devices. SIGMOD 2016, sections 3-5.
- Dayan and Bonnet. Garbage Collection Techniques for Flash-Resident Page-Mapping FTLs. arXiv:1504.01666v1, sections 5-6.
Sources & caveats
- Source synthesis, not an implementation replication. The 2015 precursor and SIGMOD 2016 paper are distinct versions; their algorithms and evaluation results should not be silently combined.