Transactional flash (TxFlash) is a novel solid-state drive (SSD) that uses flash memory and exports a transactional interface (WriteAtomic) to the higher-level software. The copy-on-write nature of the flash translation layer and the fast random access makes flash memory the right medium to support such an interface. We further develop a novel commit protocol called cyclic commit for TxFlash; the protocol has been specified formally and model checked.

Our evaluation, both on a simulator and an emulator on top of a real SSD, shows that TxFlash does not increase the flash firmware complexity significantly and provides transactional features with very small overheads (less than 1%), thereby making file systems easier to build. It further shows that the new cyclic commit protocol significantly outperforms traditional commit for small transactions (95% improvement in transaction throughput) and completely eliminates the space overhead due to commit records.

In: Proceedings of the 8th USENIX Symposium on Operating Systems Design and Implementation (OSDI ’08)

Publisher: USENIX
All copyrights reserved by USENIX 2007

Details