In this video from ITFreeTraining, I will have a closer look at the traditional options
available in Windows to combine multiple disks together, as well as having a closer look
at basic and dynamic disks.
This video assumes you know the basic ways and terminology on
how disks can be combined together using systems like RAID.
If you do not understand how to
combine drives using Raid 0, mirroring and Raid-5, see our introduction video on Raid
and storage solutions.
With Windows 8 and Windows Server 2012, Microsoft added Windows Storage Spaces aimed to replace
the traditional options provided by Logical Disk Manager in Windows.
For more information
about Windows Storage Spaces, please see our Windows Storage Spaces video.
Before I start looking at how multiple disks can be combined together in Windows, I first
need to look at basic and dynamic disks.
Basic and Dynamic disks are two types of disk configurations
that Windows supports.
Basic disks are the older standard and offer the most compatibility.
This compatibility goes back to MS-DOS days.
If you want to ensure the disk can be used
on different systems, including Linux systems, the basic disk is the best choice.
Dynamic disks offer more features than basic disks.
For example, dynamic disks are required
to combine multiple drives together to form one volume.
Once a disk is changed from a
basic disk to a dynamic disk it requires Logical Disk Manager.
Logical Disk Manager was developed
by Microsoft and include with Windows.
Dynamic disks were introduced in Windows 2000 and, thus, work with almost all editions of
Windows released after Windows 2000.
Since it has been around so long, support has been added in Linux for dynamic disks.
If you plan to use dynamic disks with Linux, check the distribution you are using and how
0:02:00.310,0:02:06.560 well it is supported.
It should be remembered that dynamic disks are a Microsoft proprietary
format.
Because of this, the Linux distribution you are using may not be able to be installed
on a disk that has been made into a dynamic disk.
In some cases even though support is
there, additional packages may need to be installed to access dynamic disks in Linux.
Basic disks are just that, one disk with basic features on it.
The only real feature that
basic disks have is the ability for the size of a volume on the disk to change.
That is,
it can be made bigger or smaller.
If the volume is to be made larger, there needs to be contiguous
free space after the volume.
Contiguous meaning uninterrupted free space after the end of
the volume.
You cannot, for example, use free space that is split into two parts.
The free
0:02:58.230,0:03:04.430 space must be at the end of volume and must
not be interrupted.
If a volume is to be made
smaller, all the free space must be at the end of volume.
If it is not, a disk defragmentation
will need to be perform first before the volume size can be reduced.
The next advantage of basic disks is that they can be booted from.
Dynamic disks, in
contrast, support booting for some multi disk configurations.
When multiple dynamic disks
0:03:28.620,0:03:33.760 have been combined together to form what is
referred to as a volume, certain configurations
do not support booting the operating system and thus they can only be used as a data volume.
*The* main advantage of dynamic disks over basic disks is that they allow multiple disks
to be combined together to form the one volume.
Windows supports a one way conversion from a basic disk to a dynamic disk.
If you convert
a basic disk to a dynamic disk and decide later on that you want to use a basic disk,
all the data on the disk will need to be removed before the disk can be made into a basic disk
0:04:07.030,0:04:12.390 again.
In a moment, I will have a look at how multiple disks can be combined together
to create the one volume.
Before I do that, I will first look at which operating systems support Dynamic disks.
All
Windows Servers after Windows Server 2000 support dynamic disks.
The vast majority of
operating systems support dynamic disks; However, in some cases, in particular with the older
operating systems, a business edition is required.
For example, in Windows XP the professional
edition is required and dynamic disks would not work on the Home Edition.
If the operating
0:04:46.300,0:04:51.350 system that you are using does not support
dynamic disks, none of the options for combining
multiple disks together that I will now look at will work.
All of these methods for multiple disks require dynamic disks.
If you attempt to use a basic
disk in any of the following configurations, Windows will prompt you to upgrade the basic
disk to a dynamic disk.
The first method is spanned volume . A spanned volume combines
0:05:13.570,0:05:18.720 the space from multiple disks together to
form a single volume.
It is a good way to
combine space; However, it does not offer any speed or redundancy features and does
not support booting the operating system.
The next method of combining multiple disks together is called mirroring.
A mirrored volume
is a fault-tolerant volume whose data is duplicated on two physical disks.
All of the data on
one volume is copied to another disk to provide data redundancy.
If one of the disks fails,
the data can still be accessed from the remaining disk.
Mirroring is also the only multi disk
option that supports booting.
Since both disks contain the same data, the operating system
does not require additional software to access the volume and this is why the operating system
0:06:02.880,0:06:06.160 can be booted from this drive.
The next volume type is striped volume . This volume type requires 2 or more disks.
Data
from the volume is spread evenly across all the disks.
Striped volumes do not offer any
redundancy but do offer improved read and write performance and once again do not support
0:06:25.310,0:06:30.530 booting.
Striped volumes are often used when performance is required but redundancy is
not.
The last volume type is RAID-5.
RAID-5 is a fault tolerant volume where the data from
the volume is striped across 3 disks or more.
As it is fault tolerant, one drive is lost
to what is referred to as parity - meaning that it can survive one drive failure and
0:06:50.020,0:06:51.770 still function.
Since multiple drives have been combined together, this gives excellent read performance.
However,
since all drives must be accessed in order to write data to the drive, write performance
is slow.
Raid-5 is only available in Windows Server operating systems and thus not available
on client operating systems such as Windows 8.
It also does not support booting.
If you
want to use RAID-5 to boot the OS you will need to use a hardware solution.
This has been a quick introduction video on dynamic disks and combining multiple disks
together in Windows.
In the next video, I will put all this together and perform a demonstration
showing how to use all these features in Windows.
Till that video, thanks for watching and see
you next time.