What is raid ?

Discussion in 'Computer Forum' started by just in hell, Mar 8, 2010.

  1. just in hell New Member

    Member Since:
    Feb 17, 2010
    Message Count:
    63
    Likes Received:
    1
    RAID: Redundant Array of Independent (or Inexpensive) Disks. Type of disk, often used on servers, where several physical disks are combined into an array for better speed and fault tolerance.
    Level 0 implements data striping where file blocks are written to separate drives. Does not provide fault tolerance, because failure of one drive will result in data loss.
    Level 1 implements data mirroring. Data is duplicated on two drives either through software or hardware. Provides faster read performance than a single drive.
    Level 2 - not used in practice. Data is split at bit level at written to multiple drives.
    Level 3 - requires at least 3 drives. Data block is striped at byte level across drives and error correction codes (parity info) is recorder on another drive. Provides fault tolerance but slower writing performance.
    Level 4 - Similar to Level 3 but provides faster performance because it uses blocks for striping.
    Level 5 - Similar to Level 4 but improves performance but also striping parity info across multiple drives.
    Level 6 - Similar to Level 5 but also uses second parity scheme for better fault tolerance.
    Level 7 - Proprietary RAID design by Storage Computer Corporation. Faster than other levels because it uses multiple levels of cache and asynchronous I/O transfers.
    In addition multiple RAID levels can be combined to improve performance or reliability.
  2. tulipkiya Member

    Member Since:
    Feb 9, 2010
    Message Count:
    197
    Likes Received:
    1
    That one i alwasy heard..but never knew this much about it...thanks man....for the good addon knowledge.
  3. syeds New Member

    Member Since:
    Mar 22, 2010
    Message Count:
    24
    Likes Received:
    1
    raid??????
  4. chris34 New Member

    Member Since:
    Jan 9, 2010
    Message Count:
    95
    Likes Received:
    3
    Occupation:
    web processor
    Location:
    U.K
    Hi guys

    In 1987, Patterson, Gibson and Katz at the University of California Berkeley, published a paper entitled "A Case for Redundant Arrays of Inexpensive Disks (RAID)" . This paper described various types of disk arrays, referred to by the acronym RAID. The basic idea of RAID was to combine multiple small, inexpensive disk drives into an array of disk drives which yields performance exceeding that of a Single Large Expensive Drive (SLED). Additionally, this array of drives appears to the computer as a single logical storage unit or drive.
    The Mean Time Between Failure (MTBF) of the array will be equal to the MTBF of an individual drive, divided by the number of drives in the array. Because of this, the MTBF of an array of drives would be too low for many application requirements. However, disk arrays can be made fault-tolerant by redundantly storing information in various ways.
    Five types of array architectures, RAID-1 through RAID-5, were defined by the Berkeley paper, each providing disk fault-tolerance and each offering different trade-offs in features and performance. In addition to these five redundant array architectures, it has become popular to refer to a non-redundant array of disk drives as a RAID-0 array.


    Thanks for all friends
  5. fizzer New Member

    Member Since:
    Feb 25, 2011
    Message Count:
    396
    Likes Received:
    0
    Location:
    everything-underthe-sun.blogsp
    still didn't get what the hell this raid si,,,,,,,,,,,,?
  6. signity New Member

    Member Since:
    Dec 13, 2010
    Message Count:
    66
    Likes Received:
    0
    Nice info and is really interesting. Thanks!
  7. zslwork Member

    Member Since:
    Jan 11, 2011
    Message Count:
    79
    Likes Received:
    0
    Location:
    US
    but now a days after arrival of new SATA drives makes this technique more reliable and worth able.
    this makes the new generation computer in the market
  8. dellinqwartz New Member

    Member Since:
    Apr 13, 2011
    Message Count:
    31
    Likes Received:
    0
    Raid is Short for Redundant Array of Independent Disks, a class of dicks drives that apply two or added drives in aggregate for accountability altruism and performance. RAID disc drives are acclimated frequently on servers but aren't about all-important for claimed computers. RAID allows you to store the same data redundantly in a balanced ay to improve overall performance.
  9. paullopez Member

    Member Since:
    Nov 5, 2010
    Message Count:
    329
    Likes Received:
    8
    Occupation:
    Sales & Marketing
    Location:
    Newark, DE, US
  10. fizzer New Member

    Member Since:
    Feb 25, 2011
    Message Count:
    396
    Likes Received:
    0
    Location:
    everything-underthe-sun.blogsp
    I searched in google and then found out that only there are 6 raid levels and we have 01,10 raids.
    So, from does level from ? Is it 10 or 01 or something else ?

Share This Page