A: The table below summarizes the main features that are supported on NTFS but not on the Windows Server 2012 ReFS file system.

NTFS should still be used for most scenarios and will be around for a long time. ReFS is a specialized file system for specific purposes today that handles a subset of what NTFS does, without having all the overhead that NTFS has. Note that ReFS supports Cluster Shared Volumes and BitLocker, so it's not on this list.

 

Functionality

NTFS

ReFS

Named Streams

Yes

No

OBJECT IDs

Yes

No

File System Compression

Yes

No

File System Encryption

Yes

No

TRANSACTIONS

Yes

No

Sparse Files

Yes

No

Hard Links

Yes

No

Extended Attributes

Yes

No

Quota

Yes

No

Max size of a single file

(264-1) bytes

(264-1) bytes

Max size of a single volume

Roughly 256 TB

Roughly 4.7 ZB (zettabytes)

Max number of files in a directory

No actual limitation

2^64

Max number of directories in a volume

No actual limitation

2^64

Max file name length

32K unicode characters

32K unicode characters

Max path length

 32K

32K

Boot to file system

Yes

No

Supported on removable media

Yes

No

Deduplication

Yes

No

WDS

Yes

No

Note also that ReFS only uses a 64KB cluster size, which means a lot of wasted space for disks with lots of small files. Since ReFS uses a Copy on Write mechanism, there's a greater chance of fragmentation.