Although Windows Server 2019 is designed to take advantage of remote storage and cloud computing, the configuration of local storage remains an important consideration.
A Windows server can conceivably perform its tasks using the same type of storage as a workstation; that is, one or more standard hard disks connected to a standard drive interface such as Serial ATA (SATA). However, the I/O burdens of a server are different from those of a workstation; a standard storage subsystem can easily be overwhelmed by file requests from dozens or hundreds of users. In addition, standard hard disks offer no fault tolerance and are limited in their scalability. A variety of storage technologies are better suited for server use. The process of designing a storage solution for a server depends on several factors, including the following:
The amount of storage the server needs
- The number of users who will be accessing the server at the same time
- The sensitivity of the data to be stored on the server
- The importance of the data to the organization
The following sections examine these factors and the technologies you can choose when creating a plan for your network storage solutions.
How many servers do I need?
When is one big file server preferable to several smaller ones? This is one of the most frequently asked questions when planning a server deployment. In the past, you might have considered the advantages and disadvantages of using one server to perform several roles versus distributing the roles among several smaller servers. Today, however, the emphasis is on virtualization, which means that although you might have many VMs running different roles, they could all be running on a single large physical server.
If you are considering large physical servers or if your organization’s storage requirements are extremely large, you must also consider the inherent storage limitations of Windows Server 2019. The number of sites your enterprise network encompasses and the technologies you use to provide network communication among those sites can also affect your plans. If, for example, your organization has branch offices scattered around the world and uses relatively expensive wide area network (WAN) links to connect them, it would probably be more economical to install a server at each location than to have all your users access a single server by using the WAN links.
Within each site, the number of servers you need can depend on how often your users work with the same resources and how much fault tolerance and high availability you want to build into the system. For example, if each department in your organization typically works with its own applications and documents and rarely needs access to those of other departments, deploying individual servers to each department might be preferable. If everyone in your organization works with the same set of resources, centralized servers might be a better choice.
Estimating storage requirements
The amount of storage space you need in a server depends on a variety of factors, not just the initial requirements of your applications and users. In the case of an application server, start by allocating the amount of space needed for the application files themselves plus any other space the application needs, as recommended by the developer. If users will be storing documents on the server, then allocate a specific amount of space for each user the server will support. Then factor in the potential growth of your organization and your network, both in terms of additional users and additional space required by each user and of data files and updates to the application itself.
Using Storage Spaces
Windows Server 2012 R2 includes a disk virtualization technology called Storage Spaces, which enables a server to concatenate storage space from individual physical disks and allocate that space to create virtual disks of any size supported by the hardware. This type of virtualization is a feature often found in SAN and network-attached storage (NAS) technologies, which require a substantial investment in specialized hardware and administrative skill. Storage Spaces provides similar capabilities by using standard direct-attached disk drives or simple external “Just a Bunch of Disks” (JBOD) arrays.
Storage Spaces uses unallocated disk space on server drives to create storage pools. A storage pool can span multiple drives invisibly, providing an accumulated storage resource that administrators can expand or reduce as needed by adding disks to or removing them from the pool. By using the space in the pool, administrators can create virtual disks of any size.
Once created, a virtual disk behaves just like a physical disk, except that the actual bits might be stored on any number of physical drives in the system. Virtual disks can also provide fault tolerance by using the physical disks in the storage pool to hold mirrored or parity data. After creating a virtual disk, you can create volumes on it just as you would on a physical disk. Server Manager provides the tools you need to create and manage storage pools and
virtual disks and provides you with the ability to create volumes and file system shares, with some limitations.
Understanding Windows disk settings
When you install Windows Server 2019 on a computer, the setup program automatically performs all the preparation tasks for the primary hard disk in the system. However, when you install additional hard disk drives on a server, or when you want to use settings that differ from the system defaults, you must perform the following tasks manually:
- Select a partitioning style Windows Server 2019 supports two hard disk partition styles: the master boot record (MBR) partition style and the GUID (globally unique identifier) partition table (GPT) partition style. You must choose one of these partition styles for a drive; you cannot use both.
- Select a disk type Windows Server 2019 supports two disk types: the basic disk type and the dynamic disk type. You cannot use both types on the same disk drive, but you can mix disk types in the same computer.
- Divide the disk into partitions or volumes Although many professionals use the terms partition and volume interchangeably, it is correct to refer to partitions on basic disks and volumes on dynamic disks.
- Format the partitions or volumes with a file system: Windows Server 2019 supports the NTFS file system, the FAT file system (including the FAT16, FAT32, and exFAT variants), and the new ReFS file system (covered later in this chapter, in the “Understanding file systems” section.)
The following sections examine the options for each of these tasks.
Selecting a partition style
The term partition style refers to the method that Windows operating systems use to organize partitions on the disk. Servers running Windows Server 2019 computers can use either of the following two hard disk partition styles:
- MBR: The MBR partition style has been around since before Windows and is still a common partition style for x86-based and x64-based computers.
- GPT: GPT has existed since the late 1990s, but no x86 version of Windows prior to Windows Server 2008 and Windows Vista supports it. Today, most operating systems support GPT, including Windows Server 2019.
Before Windows Server 2008 and Windows Vista, all x86-based Windows computers used only the MBR partition style. Computers based on the x64 platform could use either the MBR or GPT partition style, as long as the GPT disk was not the boot disk.
Unless the computer’s architecture provides support for an Extensible Firmware Interface (EFI)–based boot partition, it is not possible to boot from a GPT disk. If this is the case, the system drive must be an MBR disk and you can use GPT only on separate non-bootable disks for data storage.
When you use Server Manager to initialize a disk in Windows Server 2012 R2, it uses the GPT partition style, whether it is a physical or a virtual disk. There are no controls in Server Manager supporting MBR, although it displays the partition style in the Disks tile.
Understanding disk types
Most personal computers use basic disks because they are the easiest to manage. Advanced volume types require the use of dynamic disks. A basic disk using the MBR partition style organizes data by using primary partitions, extended partitions, and logical drives.
A primary partition appears to the operating system as though it is a physically separate disk and can host an operating system, in which case it is known as the active partition. When you work with basic MBR disks in Windows Server 2019 using the Disk Management snap-in, you can create three volumes that take the form of primary partitions.
When you create the fourth volume, the system creates an extended partition, with a logical drive on it, of the size you specified. If there is free space left on the disk, the system allocates it to the extended partition where you can use it to create additional logical drives.
When you select the GPT partition style, the disk still appears as a basic disk, but you can create up to 128 volumes, each of which appears as a primary partition. There are no extended partitions or logical drives on GPT disks.
The alternative to using a basic disk is to convert it to a dynamic disk. The process of converting a basic disk to a dynamic disk creates a single partition that occupies the entire disk. You can then create an unlimited number of volumes out of the space in that partition.
Dynamic disks support several different types of volumes, as described in the next section.
Understanding volume types
A dynamic disk can contain an unlimited number of volumes that function much like primary partitions on a basic disk, but you cannot mark an existing dynamic disk as active. When you create a volume on a dynamic disk by using the Disk Management snap-in in Windows Server 2019, you choose from the following five-volume types:
- Simple volume Consists of space from a single disk. After you have created a simple volume, you can extend it to multiple disks to create a spanned or striped volume, as long as it is not a system volume or boot volume. You can also extend a simple volume into any adjacent unallocated space on the same disk or, with some limitations, shrink the volume by deallocating any unused space in the volume.
- Spanned volume Consists of space from 2 to 32 physical disks, all of which must be dynamic disks. A spanned volume is essentially a method for combining the space from multiple dynamic disks into a single large volume. Windows Server 2019 writes to the spanned volume by filling all the space on the first disk and then filling each of the additional disks in turn. You can extend a spanned volume at any time by adding disk space. Creating a spanned volume does not increase the disk’s read/write performance or provide fault tolerance. In fact, if a single physical disk in the spanned volume fails, all the data in the entire volume is lost.
- Striped volume Consists of space from 2 to 32 physical disks, all of which must be dynamic disks. The difference between a striped volume and a spanned volume is that in a striped volume, the system writes data one stripe at a time to each successive disk in the volume. Striping provides improved performance because each disk drive in the array has time to seek the location of its next stripe while the other drives are writing. Striped volumes do not provide fault tolerance, however, and you cannot extend them after creation. If a single physical disk in the striped volume fails, all the data in the entire volume is lost.
- Mirrored volume Consists of an identical amount of space on two physical disks, both of which must be dynamic disks. The system performs all read and write operations on both disks simultaneously so they contain duplicate copies of all data stored on the volume. If one disk fails, the other continues to provide access to the volume until the failed disk is repaired or replaced.
- RAID-5 volume Consists of space on three or more physical disks, all of which must be dynamic. The system stripes data and parity information across all the disks so that if one physical disk fails, the missing data can be re-created by using the parity information on the other disks. RAID-5 volumes provide improved read performance because of the disk striping but write performance suffers due to the need for parity calculations.