What You Need to Know About Storage Spaces to Pass Exam 70-410
Microsoft has introduced a new feature in both Windows 2012 and Windows 8 to help IT Professionals manage storage. The feature is called Storage Spaces, and it brings easy to manage RAID like storage virtualization to both the client and server operating system.
Like any new feature, there will be some discussion of Storage Spaces on the certification exams for Windows 8 and Windows 2012.
What is Storage Spaces?
Storage Spaces is a virtualization technology allowing disk resource to be grouped into pools of storage allowing disks included in a pool to be seen as one logical unit. Similar to the way that RAID operates. Doing this provides redundancy for stored data without the expense of a large disk array. Storage Spaces can be used on any disks, from an array made of Just a Bunch of Disks (JBOD) or external USB-connected hard drives.
Storage Spaces is a technology that simplifies using external storage locally on a Windows Server system. In addition to the simplification of configuration and operation, the cost of storage can be greatly reduced. Being able to use any disks that will connect to a Windows Server system, the price of storage can be greatly reduced as well. Outside of the improved ease of management, the potential for budget savings for an IT department can be pretty substantial depending on what the needs are within an organization.
How does it work?
To create a Storage Space, disks are added to a pool. Storage Spaces are created on top of the disk pool. The Storage Spaces created on a disk pool are the logical disks presented to Windows and can be thin provisioned to grow as needed. Using virtualization to allow thin provisioning of disks allows the storage to grow as needed without affecting what Windows is able to see.
For example, if a disk pool is created using two 500GB USB drives and the Storage Space is created to be 2TB in size, there is no way that the full size of the volume will fit on the drives within the disk pool. Simply adding more or larger disks to the pool can allow the logical disk to grow to the size specified.
When creating a disk pool to use with the Storage Spaces feature, the disks will be formatted for use. Any data on the disks will be lost during the initialization process. If you will be recycling disks for use with Storage Spaces, be sure that the data on the disks is backed up before you begin.
Redundancy of data
Redundancy in Storage Spaces is something that works in a similar fashion to RAID, but is not RAID technology. There are certain levels of redundancy available with Storage Spaces:
- Simplethis option does not protect data from a drive failure and only writes one copy of the data, requiring only one disk
- Two-way mirrorthis option writes two copies of stored data and will protect against a one-disk failure. It requires at least two disks.
- Three-way mirrorthis option writes three copies of stored data, requiring at least five disks, and will protect against a two-disk failure.
- Paritythis option will protect data from a single disk failure using parity information. It requires at least three disks.
In addition to redundancy across disks in the disk pool, Storage Spaces provides extremely fast recovery in the event that the computer or server running the disk pool is unavailable. Because of the meta data written to the disks in the pool about the storage spaces, and about the fact that the disks belong to a pool, the drives can be simply plugged into a computer that supports Storage Spaces (Windows Server 2012 or Windows 8) and the Storage Spaces that reside on the disk pool will be available on that system with no additional work on the part of the administrator.
When readying a disk for a Storage Space or disk pool all of the existing information on the disk will be removed during a format that happens during the process. The Storage Spaces Metadata is written to the disks at this time. As the configuration is used to store data, the Metadata is updated to ensure that no information gets lost if the disks are lost or moved to another computer.
Configuring Storage Spaces
To build a Storage Space, attach the disks to your computer; in this case I will be using removable USB hard drives, but other types of storage, including SAS and iSCSI will also work. With the media attached, complete the following steps:
- From the Control Panel, tap or click Storage Spaces.
- Select Create a new pool and Storage Space and tap or click Yes on the UAC prompt.
- External media will be discovered by the storage spaces, select the devices to include and tap or click Create Pool.
- Enter a name for the Storage Space.
- Select a drive letter for the logical volume, then choose a resiliency level.
- Tap or Click Create Storage Space.
The dialog presented for creating Storage Spaces will also display the capacity of the space based on the media used and resiliency level selected before you actually create the space, this can help in choosing a resiliency level.
Once the create button is clicked, the format happens and the Metadata is written to all disks about the disk pool and storage spaces created on it. You can create multiple Storage Spaces on a disk pool, but a disk can only belong to one pool. If a disks pool is changed, the disk will be formatted.
As soon as the initial configuration is completed, the Storage Spaces app in the control panel will refresh to display a management interface for storage spaces. This is shown in Figure B.
In addition to information about the Storage Space, information about the physical disks in the pool is also available by expanding the Physical Drives portion of the screen.
On the exam
According to the exam details posted on the Internet, Storage Spaces technologies make up about 16% of the test. Understanding the overall technology will provide much of the information needed. The concepts of Storage Spaces being created on top of physical disk pools is new at the operating system level is different from past versions of Windows.
Because the feature is new with the newest versions of Windows, take the time to understand what the feature does and how it works. Sixteen percent seems like a small amount against the overall total, and the technology should be on the exam to raise awareness of the features, which may be otherwise overlooked.