Samsung releases SSD-specific F2FS file system

October 9, 2012 // 9:30 a.m.

Tags: #f2fs #file-system #flash-friendly-file-syste #flash-friendly-file-system #linux #nand-flash #open-source #samsung #solid-state-storage #ssd

Samsung has designed and launched a new file system with a singular aim in mind: improving the longevity and performance of NAND flash-based storage devices.

Dubbed the Flash-Friendly File System, or F2FS, and developed by Samsung's Jaegeuk Kim, the new file system attempts to address some of the issues with using formats designed for spinning-disk devices on solid-state drives including those that lead to performance-sapping cleaning cycles and loss of throughput over time.

'Since [SSDs] are known to have different characteristics from the conventional rotational disks, a file system, an upper layer to the storage device, should adapt to the changes from the sketch,' Kim explains in a patch notification for the file system. 'F2FS is a new file system carefully designed for the NAND flash memory-based storage devices. We chose a log structure file system approach, but we tried to adapt it to the new form of storage. Also we remedy some known issues of the very old log structured file system, such as snowball effect of wandering tree and high cleaning overhead.

'Because a NAND-based storage device shows different characteristics according to its internal geometry or flash memory management scheme aka FTL, we add various parameters not only for configuring on-disk layout, but also for selecting allocation and cleaning algorithms.

The result, in theory, is a file system specifically tuned to solid-state storage from any vendor, improving performance, increasing longevity and allowing for fine-tuning of various parameters - such as the type of garbage collection in use - in order to achieve maximum throughput.

A file system is no good without widespread support, however - but Samsung has a trick up its sleeve to boost adoption: as Kim's patch suggests, the file system and all related utilities are being released under the GNU General Public Licence (GPL) v2, making it suitable for integration within the Linux kernel. It's a smart move: as well as giving Samsung a large number of external testers who are looking for the best performance from their hardware and don't mind the risks inherent with adopting an as-yet unproven file system, the community will be free to write fixes and enhancements which can be adopted back into the file system.

When - or, indeed, if - the file system has proved itself in the wild, it seems likely that Samsung will release a driver for Windows to add F2FS compatibility. So far, however, the company appears to be concentrating on Linux support.

If you fancy giving the file system a trial, the tools package can be downloaded from SourceForge - but be warned: thus far, there is no support for checking and repairing the file system in the event of a system crash, making data loss more than likely.