RAID for Consumer PCs

[Big_Dave]

If you have an interest in using RAID, then the MS Word document attached to this post may be useful information.  Scroll all the way to the bottom for the attachment.

RAID for Consumer PCs

Table of Contents

RAID

RAID 0

RAID 1

RAID 5

RAID 10 (0+1)

INTEL Controller Support for Different RAID Configurations

Background Information for Creating a RAID configuration.

Considerations:

Performance comparisons

Creating a RAID 0 Array

Creating a RAID 1 Array

Creating a RAID 5 Array

Creating a RAID 10 (0+1) Array

Conversion from RAID 0 to RAID 5

RAID 0 to RAID 5 Observations

Other RAID Migrations

*************DISCLAIMER***********

RAID

RAID is an acronym for Redundant Array of Inexpensive Disks and also commonly called Redundant Array of Independent Disks.  A RAID array is created when one or more hard disks or one or more solid state disks (SSD) are combined to form a logical volume using one of several different configurations.  Consumer level PCs typically use RAID 0, RAID 1, RAID 5 and occasionally RAID 10 (0+1).  The RAID configuration choice is dependent on the requirements for redundancy, speed and capacity.  The choice of a RAID configuration will be a compromise between speed, redundancy, capacity and cost.  The different RAID configuration options can be restricted by hardware limitations.

RAID 0

A RAID 0 volume is created when 2 hard disks are used and then data is spanned or striped across the different hard disks.  The process of spanning data across different hard disks is also called scatter loading.  By spreading data across multiple hard disks, a significant performance improvement can be gained.  However, should one of the hard disks fail, then the entire RAID 0 configuration becomes unusable.  A RAID 0 volume combines the capacity of the hard drives being used in the configuration.

RAID 1

A RAID 1 configuration is created when 2 hard disks are used and then data on hard drive 1 is replicated to hard drive 2.  The process is also called data mirroring.  This configuration provides for redundancy in the event of a single hard drive failure but at the expensive of a degradation to write performance as data has to be written to multiple hard drives.  Since the data is being replicated between two volumes the overall capacity is limited to that of one hard drive.

 

RAID 5

A RAID 5 configuration is similar to a RAID 0 array except RAID 5 deploys distributed parity also referred to as checksum data.  Blocks of data are stripped across three or more hard drives and each hard drive contains block level recreation data (parity).  In the event of a hard drive failure, parity will allow for the data to be accessed through a dynamic data creation process.  The downside to the dynamic data creation process is a reduction in performance until the failing hard drive can be replaced.  RAID 5 performs best for supporting read accesses as write operations will be slower while the parity blocks are being updated.  Parity data does consume disk space.  A three hard drive RAID 5 array will have about the same total data capacity as a two hard drive RAID 0 array.

RAID 10 (0+1)

A RAID 10 configuration also called RAID 0+1 can be implemented in two different methods depending on the hardware being used.  The below left configuration is a striped RAID 1 array being replicated and the below right configuration is a RAID 0 array being replicated.  A RAID 10 configuration can provide a RAID 0 performance level even with the loss of one hard disk.  The downside to RAID 10 is the reduced configuration capacity.

INTEL Controller Support for Different RAID Configurations.

The RAID configurations used in this document are based on the INTEL SATA controller.

See the below table.

NOTE: Even though your system board may have the appropriate Intel controller,

not all system boards will provide RAID functionality.

Background Information for Creating a RAID configuration.

You can create a RAID configuration provided that:

1. The PC cabinet can accommodate additional hard drive(s) if needed.
2. The system board has the necessary open SATA port(s) if needed.
3. A SATA controller that can support the desired RAID configuration.

You can determine the status of your RAID configuration by using the Intel Rapid Storage Technology (IRST) software.  If you don’t have this software on your PC then you can download IRST from the Intel web site.  I recommend that you use the latest version available from Intel.  Background information can be obtained from the IRST User Guide.  When you launch IRST, the help topics are an excellent source of information.  You can access IRST by going into the Control Panel and select Intel Rapid Storage Technology. You can also access IRST from the lower right Task Bar location.  IRST should resemble a hard drive icon and normally it has a green check mark.  By default IRST is set as delayed startup so don’t expect to see it active right after boot up. The Intel images being used in this document are from IRST version 11.1.0.1006.

If the SATA controller in your PC is not set to RAID then read this Microsoft article if you are running VISTA or Windows 7.  You need to run the MrFixIT script before you reboot your PC in the bios and make the SATA controller mode change to RAID.  The script will then allow Windows to choose the correct driver when you reboot your PC.  If you plan on using a boot drive image restore then be sure to run the script just prior to making taking your image backup.  That way your backup image is set to allow Windows to choose the correct SATA driver.

Before creating any RAID configuration, always make backups of your data and image the boot hard disk to external media such as an USB drive.  Additionally, be sure that your imaging product boot disk is functional, particularly if the PC’s boot hard disk is part of the RAID configuration.  Its best to use a commercial hard disk imaging product as support and functionality is generally better than the “freebie” software.

Be sure that your PC is running the latest available BIOS.  BIOS updates are used to update the Intel ROM firmware.  Additionally, check for hard drive and SSD firmware updates.

Summary of preparation steps in priority order:

1. Backup your data.
2. Test out your recovery and restore procedures.
3. Update the following: BIOS, hard drive firmware, SSD firmware
4. Update IRST
5. Execute the Microsoft MrFixIt if your PC is not set to RAID mode in the bios.
6. Create an image of your boot hard drive.

Considerations:

After replacing a failed hard drive, don’t expect the rebuild process to be fast.  All of the data that existed on the failed hard drive must be either regenerated using parity data or replicated to the new hard drive.

I recommend that you use an uninterruptable power supply (UPS) when using RAID 5. Cached write data needs to be written to hard drive in the event of a power failure to avoid the loss of data.  You might want to consider disabling write back cache if you are not using an UPS. There is a performance reduction by doing so at the expense of improving data integrity.

If you need a RAID array over 2 TB then your PC needs: UEFI bios, 64 bit operating system, GPT formated hard drives.  Review this Microsoft article on Windows and GPT FAQs.

Since a MBR formated array will limit the useable space to 2 TB it’s therefore best to use hard drives that are 1 TB or less for RAID 0, 5 and 10.

Consider the data growth rate and the size of the array.  The Intel controller will limit the number of hard drives.  The size of the PC cabinet and available system board SATA ports will also be growth constraints.  It’s not uncommon for a business to experience an annual data growth rate of 20 percent.

If you need a RAID solution beyond the typical consumer level RAID configurations, then you should review the RAID options available from HP.

RAID technology in not infalible so you need to consider backups.  A voltage spike inside your PC could render the RAID unusable and unrecoverable.  Corrupted data or a virus are other reasons for keeping backups.  An external USB connected hard drive might be sufficient for backups.

Throughly test your backup and restore software. Always keep more than one backup copy of your data.

Performance comparisons:

All of the hard drives benchmarked are Hitachi 1.5 TB SATA III hard drives connected as SATA II devices.  HD Tune was used to benchmark the seniaros using default settings.

Configuration	Average MB/s	Maximum MB/s
Single hard drive	113	152
RAID 0	222	289
RAID 1	104	142
RAID 5	221	288
RAID 10 (0+1)	220	274

Creating a RAID 0 Array.

If you are configuring the Windows boot drive into a RAID 0 array, then you need to use the Intel option ROM method for creating the array.  Tapping Cntl-i at boot up will get you into the Intel option ROM firmware setup utility.  Once the array has been created then boot up your image recovery disk and load the array from your image backup.

If you are creating a RAID 0 data only array then you can use the IRST when running Windows to create the array.  You can also use the Intel option ROM firmware setup utility.  Even though this HP VISTA RAID setup article is dated, it does have some excellent information.

Launch IRST.

You can observe in the above image the status of the hard drives attached to the Intel SATA controller.  Now click on Create. Select Optimized Disk (RAID 0) then click on Next.

Configure the RAID 0 array by selecting two hard drives of the same size and click on Next.

Next click on Create Volume.

 

A warning window will appear.  Click on OK.

The new RAID volume is now created. However, you now need to use Windows Disk Management to ready the volume for use.

Creating a RAID 1 Array.

If you are configuring the Windows boot drive into a RAID 1 array, then you need to use the Intel option ROM method for creating the array.  Tapping Cntl-i at boot up will get you into the Intel option ROM firmware setup utility.  Once the array has been created then boot up your image recovery disk and load the array from your image backup.

If you are creating a RAID 1 data only array then you can use the IRST when running Windows to create the array.  You can also use the Intel option ROM firmware setup utility.  Even though this HP VISTA RAID setup article is dated, it does have some excellent information.

Launch IRST.

You can observe the above status of the hard drives attached to the Intel SATA controller.  Now click on Create.

Select Real-time data protection (RAID 1) and click NEXT.

Configure the RAID 1 array by selecting two hard drives of the same size and click on Next.

 

Next click on Create Volume.

The new RAID volume is now created. However, you now need to use Windows Disk Management to ready the volume for use.

Creating a RAID 5 Array.

A RAID 5 array will require three to four hard drives. While it is possible to convert a RAID 0 to a RAID 5 array, I recommended that you consider building the RAID 5 array from scratch rather than use a conversion method.

If you are configuring the Windows boot drive into the RAID 5 array, then you need to use the Intel option ROM method for creating the array.  Tapping Cntl-i at boot up will get you into the Intel option ROM firmware setup utility.  Once the array has been created then boot up your image recovery disk and load the array from your image backup.

If you are creating a RAID 5 data only array then you can use the IRST when running Windows to create the array.  You can also use the Intel option ROM firmware setup utility.  Even though this HP VISTA RAID setup article is dated, it does have some excellent information.

The following procedure will build the RAID 5 array with three hard drives using IRST.

Launch IRST.

During this create process, I will be using the last three hard drives

listed in the above image under Storage System View.  Now click Create.

Select Efficient data hosting and protection (RAID 5) and click

On Next.

Select the three hard drives for RAID 5 and click on Next.

Review the volume creation selections then click on Create Volume.

Review the final warning then click on OK.

Now click on OK and review the final array status.

Creating a RAID 10 (0+1) Array.

A RAID 10 (0+1) array will require four hard drives.

If you are configuring the Windows boot drive into the RAID 10 (0+1) array, then you need to use the Intel option ROM method for creating the array.  Tapping Cntl-i at boot up will get you into the Intel option ROM firmware setup utility.  Once the array has been created then boot up your image recovery disk and load the array from your image backup.

If you are creating a RAID 10 (0+1) data only array then you can use the IRST when running Windows to create the array.  You can also use the Intel option ROM firmware setup utility.  Even though this HP VISTA RAID setup article is dated, it does have some excellent information.

The following procedure will build the RAID 10 (0+1) array using four hard drives using IRST.

Launch IRST.

This create process will be using the last four hard drives listed in the above image under Storage System View.  Notice that the hard drives are not the same size.  Two of the hard drives are 1.5 TB and two hard drives are 2 TB.  While it’s recommended to use all hard drives of the same size, it’s not required. The RAID 10 creation progam will pick to two smallest hard drives for the striped pair and then the two largest hard drives for replication pair but not the opposite as the two largest hard drives if used as the striped pair would not fit on the two smaller hard drives for replication.  Now click Create.

Select Balanced performance and data protection (RAID 10) and click

on Next.

Select the four hard drives for RAID 10 and click on Next.

Notice that IRST is set to create a RAID 10 volume with the capacity of 2.7 TB.

Review the volume creation selections then click on Create Volume.

Review the final warning then click on OK.

Now click on OK and review the final array status.

Conversion from RAID 0 to RAID 5

If you have a RAID 0 hard disk configuration and you are concerned that a hard drive failure will cause your PC to crash or results in data loss then you might have an option to use RAID 5.  A RAID 5 three drive configuration can survive a single hard drive failure but not two failing hard drives. While there are other RAID configurations possible, this document will only be addressing a three hard drive configuration using the Intel SATA controller.  Some of the newer HP PCs can accommodate three hard drives and can be configured when ordered with RAID 5.

Observe the below image.  This PC has a RAID 0 2.7 TB array.  To build the RAID 5 array, you will need to add (configure) an additional hard drive into the array. Click on Manage and then add an eligible hard drive to the array.

Note: all data on the hard drive to be added to the array will be lost since parity and data from the existing array needs to be written to the added hard drive to create the RAID 5 array.  Take backups of your existing array in case something goes wrong.

Once you are on the Manage screen then click on Change type.

The following screen will appear:

Select the drive to be included into the array and click on OK.

When the migration process begins, the Status is now indicating migrating and the Type is RAID 5.  The hard drive added was 2 TB which meets the minimum amount.  BE PATIENT!  The migration process will take a very long time for an in place migration to complete.

It’s much faster to delete out the original RAID 0 volume, create the new RAID 5 volume and then reload the original RAID 0 image from your backups. I recommend that you consider

this method verses the in place approach.

 Click on Status to show the migration progress.

RAID 0 to RAID 5 Observations

I was able to shut down and boot the RAID configuration before the migration process had completed.  The in place migration method was very slow, about 3% per hour and hence my recommendation to use a differnet method.  Booting up from different hard drive before the migration process has completed results in a BSOD on boot up.

After completing the RAID 5 conversion, I did receive a message from IRST indicating that one or more volumes is protected against a hard drive failure.

Other RAID Migrations

While there are other RAID migrations options available, they can be platform (chipset) specific.   Review this Intel Chipset article on supported RAID migrations.  Even though the Intel RAID migration has a safety function built into the process in the event of a power loss or shutdown, it’s always best to have a complete set of up-to-date backups.

The migration process can be painfully slow.  The migration time is largely dependent on the hard drive sizes and the number of hard drives involved in the overall migration.  In some cases it might be faster to build the RAID array from scratch and then load the data back to the array verses using an in place migration process.

It is possible to increase the overall RAID array (volume) size with some RAID configurations by adding hard drives to the array.   The overall size of the array may be limited by how the array had been previously formatted by Windows.  Review the information under the Considerations topic in this document.

*********updated August 21, 2013

If you are using SSDs in a RAID 0 configuration then you will need to have the Intel 7 or 8 chipset plus Intel Rapid Storage Technology (IRST) version 11 or higher to get Windows TRIM support to function. The latest version of IRST as of 8/21/2013 that I have seen is 12.7.1036.

*************DISCLAIMER***********

There may be inaccuracies with the information contained in this document so please consider that when using RAID.

*************DISCLAIMER***********

[wb2001]

Great document

[AllWeLearn]

Thanks great post, but how i can configure RAID for HP Compaq Elite 8300 Small Form Factor, is it from windows base tool or BIOS, sorry this part is not clear for me

[Big_Dave]

Hi,

If the Intel option ROM is enabled in the bios and the SATA controller mode is set to RAID then CTRL-I at boot time will allow you to configure RAID via the bios method. Else, if the SATA controller mode is set to RAID then the Control Panel method should also work.

The 8300 small form factor will only support two 3.5" hard drives and then only if you remove the card reader if present.

Depending on your storage needs, your performance requirements and the Intel storage controller chipset in your PC, you might want to consider using two SSDs in a RAID 0 configuration.

[suffhp]

A wonderful post.

I have yet to work my way through it, but it looks like "Raid for idiots" or as i was using long before the advent of "X for Idiots" , "Raid For Tots n Tinys" .

I have a raid set up, which is not performing as i would wish, so i have high hopes this will help me out.

Ive printed out the makers (Zyxel) user guide of 133 pages as well as the technical reference of 222 pages and i have read them. Yet i've found that i still do not fully appreciate how i can configure it to meet my neeeds. Something is missing, i suspect it is my inability to practice/experiment and thus to better understand what goes on.   

With high hopes, i thank you

[dkocian]

Wow.  What a fantastic amount of information.  I did not see this before I posted my own question about RAID and wish I had.  It answered almost all of my questions.  Thanks for posting this.

[ivoidwarranties]

I have a brand new HP Envy Phoenix 850se... there's not option for Ctrl + I to create a bootable RAID0 array.  I can select RAID as the option for SATA mode, but I can't seem to figure how to create a bootable RAID0 array after it's enabled.  Is it no longer an option?

[Big_Dave]

Hi,

Before you do anything, be sure to install the latest Intel IRST drivers fro the Intel site. Now set the PC to boot in safe mode via MSCONFIG. Restart the PC and boot into the BIOS and change the SATA mode to RAID.  If OK at this point, then boot up your PC.  If OK at this point then you should be in safe mode and RAID ready. Now revert the MSCONFIG safe mode change and reboot.  You can try Crtl-i but if it doesn't work then use the Intel application in the Control Panel. It takes a minute for it to initialize.

[Dave11111111]

Why does HP even use RAID 5 for desktop PCs? From what I understand if one of the drives goes, you CANNOT use windows and you are screwed.

[Big_Dave]

@Dave11111111

Did you read the definition about how RAID 5 functions?