Allocating disk space

Applies To: Windows Small Business Server 2011 Standard

Before you install Windows SBS 2011 Standard, determine the size of the hard disk or partition on which to install Windows SBS 2011 Standard. There is no set formula for determining a hard disk or partition size. The basic principle is to allow enough space for the operating system, applications, and other files that you plan to install. A minimum of 120 GB is required to install Windows SBS 2011 Standard. It is recommended that you allow considerably more disk space than the minimum. This allows space for a variety of items, including additional components, future service packs, and the paging file that the operating system uses. You also need additional space for the server applications that you plan to install.

Sample hard disk configurations

The estimates included in the following table are based on typical usage and functionality, but they do not address issues that affect optimal performance. You can use any type of supported hard disk for these configurations.

Server Level Suggested Hard Disk Configuration


  • Two physical hard disks

  • Configured as a RAID 1 mirrored set that contains the following:

    • Volume C: 250 GB

    • Volume E: 250 GB

    • Volume F: 150 GB


  • Three physical hard disks

  • Configured as a RAID 5 set that contains the following:

    • Volume C: 250 GB

    • Volume E: 250 GB

    • Volume F: 250 GB


  • Five or more total hard disks

  • Two hard disk drives in a RAID 1 mirrored set that contains volume C: 250 GB

  • All remaining disks in a RAID 5 set that contains the following:

    • Volume E: Half of the available space

    • Volume F: Half of the available space

These suggestions take into account the size of the installed operating system, the average size of the data storage that Windows SBS 2011 Standard uses and the expected data storage growth over the life of the server. The volumes can be partitions on a set of hard disks, or they can be placed on individual hard disks. Because the server can store important data for your users, it is recommended that you use multiple hard disk s and help protect your users’ data by using RAID.

The recommended volume configurations are as follows:

  • Volume C The system drive contains the operating system files, and it leaves room for files and applications such as the page file, the installed applications, and the dump files. Do not enable the Volume Shadow Copy Service on this volume. Initially, an installation of Windows SBS 2011 Standard is approximately 35 GB. However, it will likely grow over time as log files, temporary files, and other data accumulates. There is enough available space on the volume for you to install additional applications, which accumulate additional data.

  • Volume D This is the DVD drive, which is used to install Windows SBS 2011 Standard and applications.

  • Volume E This volume contains the data stores, such as the Exchange Server database, Windows Server Update Services, and Microsoft SharePoint Foundation 2010 databases. Do not enable the Volume Shadow Copy Service for this volume, because it might cause performance issues with Exchange Server.

    • Assuming that 10 people use Exchange Server, and they each need an average of 2 GB, you need to provide 20 GB to store email. Some environments need more room because of larger file sizes or because of retention requirements, so the estimates are based on 40 GB for Exchange Server data. If you provide email services for more than 10 users, this volume should be larger.

    • A typical Windows Server Update Service database is 40 GB. The estimates provide for a 50 GB database.

    • The estimates allow for 10 GB of storage for SharePoint Foundation 2010.

  • Volume F This volume contains the users’ data, including redirected user folders and shared folders. You should enable the Volume Shadow Copy Service on this volume to help back up the users’ data.

    • Windows SBS 2011 Standard automatically redirects users’ folders. This can include music, pictures, and other types of data that may require a large amount of storage space. The estimates are based on 5 GB of storage per user, with 10 users.

    • You can also store shared data in shared folders on the server. The estimate allows for 50 GB of shared storage.

    • The amount of space that the users’ data requires is the most difficult to estimate. Wherever possible, allow more space for the users’ data.

  • Volume G This volume is optional, and it is not included in the estimates. It contains low priority data that is easily recovered from another source such as a CD or DVD, and that can be excluded from normal backups.

Optional storage devices

In addition to the internal hard disks that are installed on the server, you should consider using external storage devices for backups. Ideally, there are at least two external storage devices with enough capacity to back up all of the data on the server. When you use external storage devices, they can be taken offsite each night to further protect the data after Backup finishes. It is recommended that the daily backup include all of the data on the server; although over time, this may require more capacity than the backup drives can provide.

Backup can exclude data from the backups based on the volume, but not based on individual folders. If the backups become too large, you can install another internal hard disk or attach another external storage device, configure it as the volume G, and then use it to save the excluded data. This is data that does not need to be backed up daily because it is less important or because another backup of the data is available.