Plan and Install Active Directory - MCSA Windows Server 2012 R2: Installation and Configuration Study Guide - page 166

One of the issues that IT members have had to face over the years is the problem of
rapidly growing data sizes. As we continue to rely more and more on computers, our data
continues to get larger and larger. This is where ReFS can help an IT department. ReFS was
designed specifically with the issues of scalability and performance in mind, which resulted
in some of the following ReFS features:
Availability If your hard disk becomes corrupt, ReFS has the ability to implement a sal-
vage strategy that removes the data that has been corrupted. This feature allows the healthy
data to continue to be available while the unhealthy data is removed. All of this can be
done without taking the hard disk offline.
Scalability One of the main advantages of ReFS is the ability to support volume sizes up
to 2^78 bytes using 16KB cluster sizes, while Windows stack addressing allows 2^64 bytes.
ReFS also supports file sizes of 2^64-1 bytes, 2^64 files in a directory, and the same num-
ber of directories in a volume.
Robust Disk Updating ReFS uses a disk updating system referred to as an allocate-on-
write transactional model (also known as copy on write ). This model helps to avoid many
hard disk issues while data is written to the disk because ReFS updates data using disk
writes to multiple locations in an atomic manner instead of updating data in place.
Data Integrity ReFS uses a check-summed system to verify that all data that is being writ-
ten and stored is accurate and reliable. ReFS always uses allocate-on-write for updates to
the data, and it uses checksums to detect disk corruption.
Application Compatibility ReFS allows for most NTFS features and also supports the
Win32 API. Because of this, ReFS is compatible with most Windows applications.
NTFS
Let's start with some of the features of NTFS. There are many benefits to using NTFS,
including support for the following:
Disk Quotas To restrict the amount of disk space used by users on the network, system
administrators can establish disk quotas . By default, Windows Server 2012 R2 supports
disk quota restrictions at the volume level. That is, you can restrict the amount of storage
space that a specific user uses on a single disk volume. Third-party solutions that allow
more granular quota settings are also available.
File System Encryption One of the fundamental problems with network operating systems
(NOSs) is that system administrators are often given full permission to view all files and
data stored on hard disks, which can be a security and privacy concern. In some cases, this
is necessary. For example, to perform backup, recovery, and disk management functions,
at least one user must have all permissions. Windows Server 2012 R2 and NTFS address
these issues by allowing for file system encryption . Encryption essentially scrambles all of
the data stored within files before they are written to the disk. When an authorized user
requests the files, they are transparently decrypted and provided. By using encryption, you