When we begin the discussion about understanding Windows filesystems, we have to first think about how the Windows Server 2022 machine will be used. There are four supported filesystems: FAT, FAT32, NTFS, and ReFS. FAT and FAT32 partitions may not always be an available option. As you can see in Figure 11.1, all four filesystems are available because the partition is under 4 GB.
FAT has a maximum partition size of 4 GB and FAT32 has a max partition size of 32 GB. In Figure 11.1, since it’s a 3 GB partition, all four options are available. But since most drives today are much larger than 32 GB, we will continue our focus on just NTFS and ReFS.
When you’re planning your Active Directory deployment, the filesystem that the operating system uses is an important concern for two reasons. First, the filesystem can provide the ultimate level of security for all the information stored on the server itself. Second, it is responsible for managing and tracking all this data. The Windows Server 2022 platform supports two main filesystems:
■ Windows NT File System (NTFS)
■ Resilient File System (ReFS)
Understanding Filesystems
FIGURE 11.1 Format options on Windows Server 2022
Although ReFS was new to Windows Server 2012, NTFS has been around for many years, and NTFS in Windows Server 2022 has been improved for better performance.
Resilient File System (ReFS)
Windows Server 2022 includes a filesystem called Resilient File System (ReFS). ReFS was created to help Windows Server 2022 maximize the availability of data and online operation. ReFS allows the Windows Server 2022 system to continue to function despite some errors that would normally cause data to be lost or the system to go down. ReFS uses data integrity to protect your data from errors and also to make sure that all of your important data is online when that data is needed.
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 corrupted, ReFS has the ability to implement a salvage 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 16 KB 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 number of directories in a volume.
Robust Disk Updating ReFS uses a disk updating system referred to as an allocateon- 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 written 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, you can establish disk quotas. By default, Windows Server 2022 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 2022 and NTFS address these issues by allowing for filesystem 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 can prevent the data from being used in case it is stolen or intercepted by an unauthorized user— even a system administrator.
Dynamic Volumes Protecting against disk failures is an important concern for production servers. Although earlier versions of Windows NT supported various levels of Redundant Array of Independent Disks (RAID) technology, software-b ased solutions had some shortcomings. Perhaps the most significant was that administrators needed to perform server reboots to change RAID configurations. Also, you could not make some configuration changes without completely reinstalling the operating system. With Windows Server 2022 support for dynamic volumes, you can change RAID and other
Understanding Filesystems
disk configuration settings without needing to reboot or reinstall the server. The result is greater data protection, increased scalability, and increased uptime. Dynamic volumes are also included with ReFS.
Mounted Drives By using mounted drives, you can map a local disk drive to an NTFS directory name. This helps you organize disk space on servers and increase manageability. By using mounted drives, you can mount the C:\Users directory to an actual physical disk. If that disk becomes full, you can copy all of the files to another, larger drive without changing the directory pathname or reconfiguring applications.
Remote Storage System administrators often notice that as soon as they add more space, they must plan the next upgrade. One way to recover disk space is to move infrequently used files to external hard drives. However, backing up and restoring these files can be quite difficult and time- consuming. You can use the remote storage features supported by NTFS to off- load seldom- used data automatically to a backup system or other devices. The files, however, remain available to users. If a user requests an archived file, Windows Server 2022 can automatically restore the file from a remote storage device and make it available. Using remote storage like this frees up system administrators’ time and allows them to focus on tasks other than micromanaging disk space.
Self- healing NTFS In previous versions of the Windows Server operating system, if you had to fix a corrupted NTFS volume, you used a tool called Chkdsk.exe. The disadvantage of this tool is that the Windows Server’s availability was disrupted. If this server was your domain controller, that could stop domain logon authentication.
To help protect the Windows Server 2022 NTFS file system, Microsoft now uses a feature called self- healing NTFS. Self- healing NTFS attempts to fix corrupted NTFS file systems without taking them offline. Self- healing NTFS allows an NTFS file system to be corrected without running the Chkdsk.exe utility. New features added to the NTFS kernel code allow disk inconsistencies to be corrected without system downtime. Security NTFS allows you to configure not only folder-l evel security but also file- level security. NTFS security is one of the biggest reasons most companies use NTFS. ReFS also allows folder- and file- level security.