Before we look at the management and configuration of disk and volumes, it is important to be familiar with the building blocks of a Windows Server 2016 storage system.
A filesystem is a part of the operating system that controls how files are organized, named, and stored on a volume. A filesystem manages folders, files, and the information needed to locate and access these items by local users or remote users. Windows Server 2016 supports four file systems: File Allocation Table (FAT), FAT32, NTFS, and Resilient File System (ReFS).
FAT is sometimes referred to as FAT16 and has been present since MS-DOS. FAT32 was introduced with Windows 95 OSR2 and has been supported in Microsoft Windows operating systems since then. FAT uses a 16-bit file-allocation table entry while FAT32 has a 32-bit file-allocation entry.
The following table shows a comparison between the size limits of FAT and FAT32:
| Description | FAT limits | FAT32 limits |
| Maximum file size | 4 GB (minus 1 byte) | 4 GB (minus 1 byte) |
| Maximum volume size | 4 GB | 32 GB |
| Files per volume | 65,536 | 4,177,920 |
| Maximum number of files and folders | 512 files (within the root folder) | 65,534 (within a single folder) |
Windows Server 2016 supports FAT and FAT32 for backward-compatibility with older types of software and hardware, and as a support for removable or portable storage, such as flash (USB) drives. Flash drives can be formatted with NTFS, but FAT and FAT32 still remain the filesystems of choice for this type of storage.
The main filesystem in Windows Server 2016 is NTFS, as it was in the previous Windows Server versions. Microsoft's newest filesystem is ReFS. The NTFS filesystem addresses the weaknesses and limitations of FAT and FAT32, providing support for larger volumes and file sizes and an increase in security, which is essential not only for business use, but for personal use as well. It provides more advanced features, such as encryption, disk quotas, security descriptors, and Clustered Shared Volumes, in a failover cluster.