Joined: 10 Apr 2009
Location: England UK
|Posted: Fri Apr 10, 2009 3:14 pm Post subject: RAID
|R.A.I.D - Short for Redundant Array of Independent Disks or Redundant Array of Inexpensive Disks (debatable), a category of HDDs that employ two or more drives in combination for fault tolerance and performance. RAID disk drives are used frequently on servers but aren't generally necessary for normal Computers. RAID allows you to store the same data redundantly (in multiple paces) in a balanced array to improve overall performance.
Types of RAID
Level 0 -- Striped Disk Array without Fault Tolerance: Provides data striping (spreading out blocks of each file across multiple disk drives) but no redundancy. This improves performance but does not deliver fault tolerance. If one drive fails then all data in the array is lost.
Level 1 -- Mirroring and Duplexing: Provides disk mirroring. Level 1 provides twice the read transaction rate of single disks and the same write transaction rate as single disks.
Level 2 -- Error-Correcting Coding: Not a typical implementation and rarely used, Level 2 stripes data at the bit level rather than the block level.
Level 3 -- Bit-Interleaved Parity: Provides byte-level striping with a dedicated parity disk. Level 3, which cannot service simultaneous multiple requests, also is rarely used.
Level 4 -- Dedicated Parity Drive: A commonly used implementation of RAID, Level 4 provides block-level striping (like Level 0) with a parity disk. If a data disk fails, the parity data is used to create a replacement disk. A disadvantage to Level 4 is that the parity disk can create write bottlenecks.
Level 5 -- Block Interleaved Distributed Parity: Provides data striping at the byte level and also stripe error correction information. This results in excellent performance and good fault tolerance. Level 5 is one of the most popular implementations of RAID.
Level 6 -- Independent Data Disks with Double Parity: Provides block-level striping with parity data distributed across all disks.
Level 0+1 -- A Mirror of Stripes: Not one of the original RAID levels, two RAID 0 stripes are created, and a RAID 1 mirror is created over them. Used for both replicating and sharing data among disks.
Level 10 -- A Stripe of Mirrors: Not one of the original RAID levels, multiple RAID 1 mirrors are created, and a RAID 0 stripe is created over these.
Level 7: A trademark of Storage Computer Corporation that adds caching to Levels 3 or 4.
RAID S: (also called Parity RAID) EMC Corporation's proprietary striped parity RAID system used in its Symmetrix storage systems.
Setting up RAID (Windows XP)
Most motherboards are able to install RAID and you can download the RAID drivers from the Motherboards web site 99% of the time to FDD, my Motherboard Supports RAID 0, 1, 0+1, 5 and JBOD - nVIDIA MediaShield RAID". You will need two HDDs of the same capacity and preferable the same make, RAID 0 "or Striping" will turn two 80GB HDDs in to one 160GB drive.
One thing to remember When deciding to move to a RAID configuration, make sure you have adequate power supply, Some RAID Arrays have been known to take more than the normal amount of power to function adequately.
When the drives have been installed to their SATA connections "and if your are to have your OS "operating system" on a none RAID drive make sure this drive is not connected".
1) Have your Motherboard Manual at hand 2) Start your PC and enter BIOS 3) Look in manual and find where you enable RAID on the motherboard 4) Enable it 5) Exit and save to CMOS 6) After BIOS Post, the RAID BIOS will show. Press the listed keys to enter the RAID Configuration BIOS (your motherboard will show you what keys to press) 7) Listed in the RAID BIOS will be several options >
-Automatically configure a RAID setup (some RAID controllers only)
-Manually set up RAID Array
-Delete RAID Array
8.) Select manually set up RAID Array - 9) Make these choices "for RIAD 0" >
-Select RAID 0
-64K Stripe Size (64k is the best performing size for all applications, especially video files and gaming)
-Select the drives
-Select the Array to be a Boot Device (only available on some RAID Controllers)
-Place Windows CD in CD Drive
-Exit RAID Set up utility
10) After boot, windows will begin to load, at the first blue screen; it will ask you to press F6 to load RAID drivers. Press F6 11) Once windows finishes placing info to memory it will show the screen to load the drivers for RAID. It will ask you to press "S" to load new storage device, press "s" 12) A new screen will ask you to place floppy in and press enter, do this 13) It will then show the drivers, press enter to select 14) The previous driver entry screen will appear showing your selected RAID drivers; press enter to allow windows to finish loading its file to memory 15) At this point if you donít want your OS on the RAID array exit Windows, if you do 16) Continue entering a clean install of windows and select your partition size 17) Format partition with NTFS and load windows to c: (once drive is formatted and windows loads files and wants to reboot, remove floppy) 18 ) Allow windows to boot and begin proper install (Do not press a key to run from CD at this point) 19) Once it boots into windows desktop you can begin regular installation of your programs, no other extra steps are needed. One thing to remember with RAID if the array goes down you stand the chance of loosing all data. RAID undoubtedly offers more data protection than non-RAID disk systems. However, the management of the disks and the data distribution across them can be complex. Complex redundant systems can suffer failure, most often not a fault of the technology used or the design of the array, but most likely because of its failure to correctly apply these systems which leads to a single point of failure causing disastrous data loss.