Microsoft explained the Windows 8 new file system ReFS details

in early December. We have reported that the new file system used by Windows 8
is officially named ReFS. Today's Microsoft Windows department leader Steven Sinofsky wrote an article on Building Windows 8
to explain the principles of ReFS and some details of the underlying architecture. The key points are as follows:
— The ReFS file system will only be used initially. Part of Windows Server 8 is released, but Windows 7/Server 2008 R2/8 clients can access folders stored on the Windows Server 8 server side using the ReFS format.
— The ReFS and NTFS file systems are highly compatible, reducing the transition costs of older users to new systems. Microsoft will not give up support for NTFS for the foreseeable future, and ReFS is just a choice for users.
— The biggest feature of ReFS seems to be the addition of a "complete" state to the original file state archive/hidden/read-only/system. Once the file/folder is converted to this state (the root directory can be easily converted by the Format command, once the parent directory is transferred, the subdirectory and all its files are changed), the system will verify the integrity of the file and directory at any time. Sex, to prevent files from being destroyed (including avoiding possible damage caused by bad sectors of the disk).
— At the same time, Microsoft also uses a copy-on-write concept similar to SQL Server products, even if the disk is physically damaged, it will not lose access and can save data as much as possible
— ReFS supports astronomical numbers The file size, the size of the volume and the number of files, the maximum file size is 2^64-1 bytes, and the maximum single volume (partition) capacity is 2^78 bytes (16KB cluster size, but Windows addressing only supports 2^64). The maximum number of files in the directories and directories under each volume is 2^64, the file length can be up to 32K Unicode characters, and the path length is up to 32K.
In summary, ReFS's "Tough" file system can be built for applications such as servers and NAS that require a lot of storage, which is why Microsoft first adopted Windows Server 8, in Windows 8. Files cannot be converted in NTFS and ReFS. In addition, ReFS cannot be used as a file system for system partitions and removable storage such as USB flash drives. It does not support NTFS EFS and compression features.

ReFS schematic bottom