Good old Windows is the operating system a lot of us grew up on, and while Microsoft is constantly seeking to keep it modern and up-to-date by adding brand-new features and fixing existing bugs, each new version (with a few exceptions) surprisingly feels just like the previous one, and as far as the interface is concerned, you probably already know every corner of this OS like the back of your hand. But what about its inner workings? For instance, do you know how it actually stores your data? Sure, you’re obviously familiar with File Explorer, but this is only the surface: if you look deeper, all the data on the hard drive of your PC is organized in a complex structure determined by NTFS – Microsoft’s primary file system employed on internal HDs and SSDs of almost every desktop and laptop computer run by Windows OS, which, by the way, still dominates the market with a substantial 90% share.
NTFS, which stands for the New Technology File System, was developed by Microsoft in 1993 and introduced with the first version of the Windows NT operating system, offering a number of significant improvements over their older FAT file system, which has been in use since the early 1980s. Nowadays, NTFS is responsible for managing data on virtually all Microsoft’s Windows 10, Windows 8, Windows 7, Windows Vista and Windows XP machines. Windows Server computers generally utilize NTFS as well, and what is more, some users format their external hard drives, USB sticks and even memory cards with NTFS to address size limitation problems imposed by FAT or to get enhanced security features.
Like in FAT, all files in NTFS are broken into clusters, each containing a number of 512-byte sectors, but, in contrast, NTFS keeps track of all the contents of your drive in a special file called the Master File Table or MFT, which can be considered the heart of the whole file system. MFT is essentially a relational database, in which each file and directory stored on the disk is represented by its own entry consisting of its name and a list of attributes which tell the operating system how to deal with this file/directory.
In fact, every file in NTFS is just a collection of its attributes, and even the data it contains is viewed just as another attribute. If a file is considerably small and all of its attributes, including the “data” attribute, can fit within one MFT entry, it will simply be stored there. Consequently, such files do not take additional storage space on the disk and can be accessed very quickly, which significantly increases performance.
However, some files are too large and their “data” attributes need more space than one MFT entry can provide. In this case, the “data” attribute of such a file is stored in blocks of clusters (called extents) outside the MFT, while its MFT entry contains pointers to this data (the number of a starting cluster and the contiguous chain of clusters it consists of). Still, it may happen that a file is so large that there is not enough room even for its all “data” attribute pointers, then the list of these pointers is itself stored outside the MFT. The MFT entry of this file will contain a pointer to a second MFT entry that contains the list of pointers to the data stored outside the MFT. When very large files are created, NTFS keeps extending this flexible structure, so, apparently, the larger the file, the more complex the storage structure becomes.
Even so, such a scheme makes it easier to manage files and improves performance reducing the number of times the system has to access the disk to locate a file. Additionally, there are several more features that make NTFS more powerful than its predecessors:
NTFS keeps track of all file and directory changes and records them to a special log or journal, so, when a problem occurs, which renders the system inaccessible or corrupt, it can be rolled back to the previous well-working state. Moreover, NTFS doesn’t perform any action to the disk until its successful completion is verified.
All file names in NTFS are stored in a format called Unicode (the most universal and widespread character encoding standard), that is why they are always displayed correctly and files themselves remain accessible, no matter what encoding was used by default.
The administrator is able to set permissions on specific files and folders and thus control who can access them, which guarantees privacy. Permissions can be applied to individual users as well as user groups.
NTFS can encrypt and decrypt files and folders while reading or writing them, preventing any unauthorized access to their contents.
NTFS allows storing very large files and partitions and can successfully deal with them without performance degradation. Files up to 16 TB are supported, with the maximum volume size up to 256 TB.
The administrator can monitor and control the amount of disk space used by each user.
NTFS enables you to compress individual files, folders or even whole drives when you’re running out of disk space. Besides, the compressed files are automatically decompressed during the process of their reading by any Windows-based application, so there is no need to decompress them using an additional utility.
NTFS adopts relatively small clusters, the size of which ranges from 2 KB to 32 KB, depending on the size of the disk, preventing wasted disk space due to cluster waste/slack.
In contrast to FAT, NTFS makes intelligent choices about where to store file data on the disk, minimizing file fragmentation ‒ a phenomenon which occurs when file segments are scattered throughout the disk, instead of being stored in one continuous chain.
If a certain file was accidentally deleted from NTFS, its attributes (name, size, position) still remain in the Master File Table record, making it almost 100% recoverable. The same goes for mistakenly formatted NTFS drives. The recovery procedure can be easily performed by one of the following utilities: Raise Data Recovery for NTFS, UFS Explorer Standard Recovery and UFS Explorer Professional Recovery.
But, on the other hand, NTFS has some disadvantages every user should be aware of:
NTFS can be fully utilized only with all recent versions of Windows ‒ all the way back to Windows XP, while its compatibility with other operating systems is very limited. For instance, macOS is able to read NTFS-formatted drives, but is not able to write any information to them without the help of third-party software. Some distributions of Linux do support writing to NTFS, and some provide just read-only access. In addition, none of Sony’s PlayStation game consoles can work with NTFS, and, on top of that, even Microsoft’s own Xbox 360 doesn’t support this file system, not to mention various non-Microsoft devices. This limitation makes NTFS a bad choice for cross-platform data sharing: for example, if you use multiple operating systems on the same computer, the ones that don’t belong to the Windows family may fail to work with an NTFS-formatted storage. Needless to say that this drawback prevents many users from employing NTFS on their external storage devices such as USB sticks.
Space overhead is some storage space on the drive which cannot store any user data as it is used by the file system itself. To function normally, on a 100 MB partition NTFS needs at least 4 MB of space overhead, making about 4% of disk space lost on its needs. Hence, formatting smaller storage devices such as memory cards or USB flash drives, especially those with the capacity less than 400MB, may result in reduced performance or inefficient use of storage space.
NTFS does not differentiate between capital letters and lowercase letters in the names of files. Also, the length of the name of a file or folder cannot exceed 255 characters and such symbols as “?,” “”,” “/,” “\,” “<,” “>,” “*,” “|,” “:” are not allowed in file/folder names.
Provided your computer runs any version of Windows, its internal hard drive is very likely to be formatted with NTFS. Still, if you have any doubts, you may check that using File Explorer: open a drop-down menu by right-clicking the drive in question, choose Properties and open the General tab. The file system type will be listed right there. By the way, the same applies to any external storage medium.
On the whole, no file system is perfect for all situations, and NTFS is really worth employing when it comes to internal or external hard drives that are used in the Windows environment only, but it won’t be suitable for the cases when compatibility is a concern.