LCE-EU 2015

Open-channel SSDs enable the host to undertake responsibilities that in typical SSDs are assumed by the Flash Translation Layer (FTL) embedded in the device. From the application perspective, this means that storage policies that have traditionally been based on best efforts can now be tailored for each specific application. In other words, applications can implement their own FTLs and govern data placement and garbage collection.

In this talk we explain how to integrate an application FTL with LightNVM - the kernel subsystem providing support for Open-Channel SSDs. More specifically, we report on the design and implementation of a LightNVM backend for RocksDB. We will focus on both the LightNVM interfaces to which other applications could hook to, and the modifications to RocksDB so that it can communicate with LightNVM. We also provide some experimental results on real hardware.