Tech Tip of the Day: RAID by the numbers

Description: This guide will walk through the 3 most common types of RAID (Redundant Array of Independent/Inexpensive Disks) and their purpose.

RAID 0

RAID 0 is not a true RAID as there is no redundancy with RAID 0. RAID 0 is typically referred to as a performance RAID as it takes all of your data and stripes it across two drives. The idea behind this RAID is that with two drives actively accessing all of your data it could theoretically be accessed twice as fast. Statistically this is not accurate, though performance is increased.

Advantages
• Faster load times/speed increase
• Uses the capacity of both disks
  
  
Disadvantages
• No redundancy - one drive fails all data is lost
  
  

RAID 1

RAID 1 is most commonly referred to as a mirrored RAID. RAID 1 takes all of your data and duplicates it exactly between the two drives in a RAID. Should one drive fail within the RAID 1 setup the other drive will take over as the primary drive without any data loss. The failed drive can then be replaced and the RAID array rebuilt in order to re-establish the mirror between the two drives.

Advantages
• Data Redundancy
• One drive fails the other keeps going
  
Disadvantages
• Requires 2 hard drives of equal capacity only

RAID 5

RAID 5 is somewhat of a combination of RAID 0 and RAID 1. It is a data stripe with a level of redundancy. RAID 5 uses three separate hard drives and stripes data across all 3 drives, but there is a level of redundancy so if one drive fails the other two take over. For this reason the overall capacity of the RAID volume is the sum of two of the three drives.

Advantages
• Data Redundancy
• Increased capacity (two out of three drives in the array)
  
Disadvantages
• Requires 3 hard drives of equal capacity

For more assistance contact Technical Support here.

Tech Tip of the Day: How to configure a RAID volume on an Intel motherboard

Description: This guide will walk through how to create a RAID volume on an Intel motherboard. Most Intel motherboards will support RAID 0 or RAID 1. RAID, or Redundant Array of Inexpensive/Independent Disks is a technology that provides storage reliability through redundancy, combining multiple hard disk drives in to one logical unit wherein data is stored in multiple copies across multiple hard drives.

There are many types of RAID but the two most common are RAID 1 and RAID 0. RAID 1 is a duplicate drive, essentially Drives 1 and 2 will be exactly the same. This is done so that if either of the two drives fail, an exact copy of that drive is readily available.

Example:
Drive 1: File A, File B, File C, et cetera.
Drive 2: File A, File B, File C, et cetera.

RAID 0 is in fact not really RAID at all because it is not redundant. RAID 0 splits a file in to pieces and puts some of the pieces on Drive 1 and some on Drive 2, to increase speed. The theory is that if Drive 1 reads the first part of File A, and Drive 2 reads the second part of File A, the information is actually read twice as fast and thus the computer is twice as fast. The major downside is that this actually doubles your susceptibility to hardware failures as if one drives fails, all of the information is lost.

1. Make sure two hard drives are connected to the motherboard and are connected to the power supply.
2. Enter the standard BIOS by pressing the F2 key repeatedly on POST.
3. Once in the BIOS go to the Configuration tab, then select SATA Drives
   
   


4. Within the SATA Drives heading set the Chipset SATA Mode to <RAID>
   
   


5. Save changes and Exit.
6. After the settings have been saved, power down the machine
7. Power on the machine and immediately begin tapping the Ctrl key and the I key repeatedly. This will access the RAID BIOS.
8. The RAID BIOS will show both drives connected to the system. In this menu select Create RAID Volume
   
   


9. Select a Name for the volume and press the Tab key
   
   


10. Select the RAID type (0 or 1) using the up or down arrow keys and press Tab again.
    
    


11. Press the Tab key through the rest of the options until you get to the Create Volume option and press the Enter key.
    
    


12. A data loss warning will appear when creating a new volume: All data will be lost on both drives. Press the Y key to create the RAID volume.
    
    


13.  The two drives will show in a RAID once this is complete. Press ESC then Y to Exit the RAID BIOS then install your operating system on your drives which are now in RAID.
    
    

For more assistance contact Technical Support here.

BYO BSOD: Build Your Own "Blue Screen of Death"

(Micro Center Random Access Newsletter, January 2009)

Prices on hard drives, video cards, and processors continue to fall, and memory prices aren't too bad either. I assembled what should be a decent performance system, using an EVGA 780i motherboard, an Intel 9600 series CPU, 6GB of Corsair 1066 DDR2 memory, a pair of NVIDIA 9800 SLI video cards, and a couple of 1 TB hard drives. What occurred during the OS setup phase were a series of minor annoyances, resulting in enough delays to prevent me from documenting the system for our December newsletter. On the other hand, it allowed me to document few tips that might make your next BYO task just a bit easier.

Some of the features I wanted to include in the system were on-board RAID, eSATA (external SATA) support, SLI dual-video card support, and enough slots to handle both current and legacy technology. Making legacy hardware work with the newer systems can be as frustrating as getting old OS versions like Windows XP to support some of the new hardware; sooner or later, you will find things that just don't play well together.

MEMORY:

Memory issues are the first to appear during the OS install, not necessarily because it is incompatible or that there are timing issues, but when there is too much of it. After installation, 32-bit versions of Windows XP and Vista will not see all of the memory when you have 4 GB or more installed. This is due to the memory map used by the OS, and that there are a certain range of addresses reserved by the OS.

The result is that the OS typically reports somewhere between 3.2 GB and 3.4 GB of memory, and ignores anything more. 64-bit versions of Windows are needed to access 4GB or more. But even 64-bit versions of Windows Vista can have problems during the installation process, causing the Setup program to terminate abnormally and display a "Blue Screen" error message...

A search of the error message includes service pack updates, hot fixes and other solutions, but I finally came across a mention of too much memory. (http://support.microsoft.com/kb/929777)



The work-around is simple: remove memory to take it to 3GB or less, install Windows, and then once installed, replace your extra memory. By pulling one or more memory modules, you should then be able to install Windows Vista or XP. In my case, Windows XP still has a problem, but no longer with the memory...

STORAGE:

When installing Windows to drives configured in a RAID array, the simple approach is to configure the drives in the hardware before installing the OS. Some RAID configurations can be implemented after the install, but this is usually an exception. To be able to install an OS to a target RAID array, the setup program must either support the RAID chipset or you must load the drivers as part of the Setup process. Once drives have been configured as RAID, they will not appear as a standard IDE or SATA storage device, causing you to see something like this:

To correct this under a Windows XP Setup, try to load the SATA IDE and or RAID drivers from a floppy disk by pressing F6 at the first setup screen to specify additional drivers. (Even after loading the NVIDIA IDE-SATA driver and the SATA RAID drivers, XP still did not see my array. It turns out that was apparently due to something in my SP3 slipstream image; the original SP2 media worked fine.) One workaround is to use a standard IDE drive or to install a secondary storage adapter and load its drivers during setup. There are reports of setup errors if RAID is set to use "AHCI" instead of ATA mode
in the BIOS. If the driver load does not work, check the BIOS setup to see if there are options available for the onboard RAID configuration or if RAID setup itself has any options. You may also find SATA settings that can impact how Windows Setup sees the drives. Most SATA drives will appear to be just another IDE device reported by the BIOS, but not always.

Remember, XP only supports adding drivers from floppy during Setup. You should be able to use a USB floppy drive if you do not have one attached to the floppy controller of the motherboard. Windows Vista setup allows you to add drivers from CD or other detected storage device including optical disk, hard drive, etc.

There is another potential issue as well: The original install of Windows
XP (pre- Service Pack 2) only supports up to 128 GB drives. The result may be that Setup reports a drive much smaller than the physical capacity, or the resulting installation is not bootable. You must have SP2 or higher to access drives larger than this.

Another installation problem with storage can be triggered by using a SATA optical drive to install from. This may generate a message about the boot device not being available or something like:

Windows XP (32-bit)

A Windows Vista (64-bit) message looks almost identical except for the 64-bit
codes...

The quick fix is to attach an IDE optical drive during the installation process.
Once the OS has been installed and the chipset and storage drivers have been loaded, you can remove the drive and use the SATA optical drive instead.

Other BYO suggestions:

• If planning a Windows multi-boot configuration, install the "oldest" OS version first. Newer versions usually will detect the previous install and give you the option for a new install or to upgrade the previous version. A new install should give you your multi-boot with the fewest issues. (Check compatibility as well - if you can't find chipset or other drivers for your OS, your system may detect, but cannot use device features without them.)


• When selecting a processor for your system board, be sure to check the vendor site for compatibility. If the processor model was released after the system board was manufactured, you may need a BIOS update for it to support the new CPU. In some cases, you must install a supported CPU to flash the BIOS before the system can boot with the newer CPU installed.


• As with the CPU, check your specifications for memory, drives, video, etc. I find nothing worse than sitting down to build a system only to find one or more components are incompatible. For example, many older modems, SCSI adapters, and other hardware that works fine under XP have no support under Windows Vista.


• Build your system with a minimal configuration to install the OS, this makes for fewer things to go wrong or conflicts to occur. When you get to the OS install phase, fewer devices means fewer drivers will be requested. As you
  add new hardware, you will know exactly what drivers Windows (or any other OS for that matter) is requesting.


• Make sure to power off the power supply or surge strip when installing or changing system components. ATX power supplies feed minimal power to the system board as soon as they are connected and turned on.


• Don't forget your anti-static straps when handling components out of their packaging. I have been sparking to every doorknob and piece of electrical equipment, even with the humidifier on "high". Even if you don't feel the spark, static voltages can destroy or shorten the life of your new system if you don't take simple precautions.


• If you are building a system with a USB card reader, don't connect the device before installing Windows. Many Setup programs will support the reader as a removable drive and shift all of the hard drive and optical drive letters up, placing these devices in the first positions along with any floppy drives. On some older system boards, if you have the BIOS boot sequence configured to "Boot Other", card readers have been known to hang at system startup, waiting for the "removable drive" to report it's "ready".