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Center for Nonlinear Studies |
Magnetic RAM (MRAM), which is now shipping, has the potential to provide non-volatile, byte-addressable memory for file systems. However, current file systems are not designed to take advantage of byte-addressable RAM, but are instead optimized for block- addressed storage. This talk will describe techniques that we have developed to improve file system performance, usability, and reliability using MRAM. I will first describe mechanisms that drastically reduce the amount of MRAM needed to store metadata by taking advantage of its byte addressability. Next, I will discuss mechanisms for providing richer metadata structures using link structures stored in MRAM. These structures are possible using disk, but MRAM is necessary to make them fast enough for regular use. Finally, I will present techniques we have developed to make MRAM-based file systems orders of magnitude more reliable than disk-based file systems by using online consistency checking and aggressive software-based redundancy. By combining these techniques, we can use MRAM to build faster, more reliable file systems that provide users with better ways to find their data.