New File System- ReFS From Microsoft

ReFS is a New FileSystem from Microsoft, will initially debut with Windows 8 Server, it stands for Resilient File System. Although it is designed to be better in many dimensions, resiliency stands out as one of its most prominent features.

Main Goals of ReFS:

• Maintain a high degree of compatibility with a subset of NTFS features that are widely adopted while deprecating others that provide limited value at the cost of system complexity and footprint.
• Verify and auto-correct data. Data can get corrupted due to a number of reasons and therefore must be verified and, when possible, corrected automatically. Metadata must not be written in place to avoid the possibility of “torn writes,” which we will talk about in more detail below.
• Optimize for extreme scale. Use scalable structures for everything. Don’t assume that disk-checking algorithms, in particular, can scale to the size of the entire file system.
• Never take the file system offline. Assume that in the event of corruptions, it is advantageous to isolate the fault while allowing access to the rest of the volume. This is done while salvaging the maximum amount of data possible, all done live.
• Provide a full end-to-end resiliency architecture when used in conjunction with the Storage Spaces feature, which was co-designed and built in conjunction with ReFS

According to Microsoft, ReFS will be an always-online file system "for the next decade or more" that is architected for "extreme scale" with large volume, file and directory sizes, as well as data verification and auto-correction via checksums while maintaining compatibility with a "wide subset of widely adopted" NTFS features.

ReFS will support a maximum size of 4 PB per storage pool path and file lengths of up to 32,000 (unicode) characters, up to 2^64 (18,446,744,100,000,000,000 or about 18 quintillion) directories in a storage volume, and up to 2^64 files in a single directory. ReFS also supports, in theory, to a maximum volume size of 2^78 bytes, as Windows stack addressing is limited to 2^64 bytes, which translates to 16,384 PB. The file size limit is 2^64-1 bytes.