SQL Server Performance

stripe size for mirror and raid5

Discussion in 'SQL Server 2005 Performance Tuning for Hardware' started by avipenina, Sep 20, 2007.

  1. avipenina New Member

    Hi,
    i'm installing SQL 2K5 on Win2K3 R2 and i configure my Array like this
    Mirror - For - OS + SQL binaries
    Mirror - For - TLog
    Raid5 - For - DB's
    my question is about the stripe size that i can choose when configuring the mirror and raid
    first question, what is stripe size exactly, second ,what stripe size should i use in the configuration above?
    Thx
  2. martins New Member

    Hi,
    Here's an quote from one of Microsoft's white-papers about storage design for SQL2k5, and should answer your questions:
    Sector Size vs. Stripe Size
    The sector size is the smallest physical storage unit on the disk. The sector size is a fixed size set by the disk manufacturer, currently at 512 bytes. The stripe size refers to the unit of data that is written and accessed from a disk in a RAID system. This is a configurable value that is set when designing the storage array system. A smaller stripe size allows data to be distributed to more disks and increase I/O parallelism. Note that the stripe size of a single SQL Server extent (64 KB) is the lower limit. For the same data, a larger stripe size means the data can be stored on fewer disks and decrease the I/O distribution and the degree of parallelism. We recommend a 64 KB or 256 KB stripe size for most workloads. When the workload includes table and index range scans on tables that are larger than 100 MB, a stripe size of 256 KB allows for more efficient read-ahead.

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