MCTS 70-680: Dynamic Disks and Raid

Windows allows you to configure your hard disk to be either a basic or a dynamic disk. Basic disks offer more compatibility, being able to be used in any version of Windows and non-Windows based systems. Dynamic disks allow more features like RAID but limit the use of the hard disk to Windows based systems.

Dynamic disk demo at 08:35

Partitions
A partition is an area of the hard disk that has been defined for later use. When multiple operating systems are on the same hard disk, you will want to keep the operating systems separate from each other. You can do this by storing each operating system in a different partition on the same hard disk.

Volumes
Once a partition has been created a volume can be assigned to that partition, for example, the c drive. Software like disk manager automatically creates these partitions for you when you create a volume. A volume can also span multiple disks. For example, a volume may contain all the free space from multiple disks. This volume will appear in Windows Explorer as one drive letter; however, the data is spread out over multiple hard drives. Think of a volume as one logical, accessible storage area stored on one or more drives.

Basic disks
A basic disk in Windows has very few features but will work in all Windows operating systems including alterative operating systems. Volumes on basic disks can only use the one partition. The size of the partition on a basic disk can be resized assuming there is free space up to where you want to shrink or expand it.

Dynamic disks
Basic disks can be converted into dynamic disks. Once the disk has been converted it can't be changed back to a basic disk unless all the volumes from the hard disk are removed and thus all the data on the drive will be lost.

In order to use Dynamic disks you need to be running Windows 7 Professional or above. Dynamic disks allow volumes to be created that span multiple disks in the form of spanned, Raid 0 or Raid 1. Dynamic disks also reserve part of the drive to store data for Logical Disk Manager (LDM). This information is replicated to all the hard drives in the system. Volumes that use multiple hard disks use this information to determine which drives are in the set. If a drive is missing, Windows can use the information stored on the other hard drives to determine which drive is missing. Also if the hard drive is moved to another system, Windows can use this information to determine the configuration of the hard drive, like which drive letter it was assigned. Since dynamic disks are Microsoft solutions, they are unlikely to work in non-Microsoft operating systems.

Spanned set
A spanned set is when free space on multiple drives is combined to form one volume. The free space on each drive can be different sizes. Spanned sets do not offer any performance improvements. If one of the drives in the set fails, all the data in the spanned set is lost.

Raid 0 (Stripped)
A Raid 0 volume has two or more hard disks combined to form one volume. The free space used has to be the same on each drive. If different, the amount of space available will be the number of hard drives in the set times the hard drive with the least amount of space. Raid 0 offers performance improvements as all hard drives in the set can operate at the same time when performing reading and writing operations. If one drive in the set is lost, then all the data in the set is lost. A Raid 0 set can't be used to boot Windows.

Raid 1 (Mirror)
A Raid 1 volume combines 2 hard drives to form a set. The data on one drive is replicated on the other hard disk, meaning that if one drive is lost the data is still available on the other hard disk. Mirror sets offer no performance improvements but Windows can be booted from a Raid 1 set.

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