SQL Server Performance

Diskpart information

Discussion in 'SQL Server 2005 Performance Tuning for Hardware' started by XiNull, Feb 1, 2007.

  1. XiNull New Member

    I've figured out how to align my disk using diskpart...running <create partition primary align=32 size=16384> in diskpart. Maybe i'm not understanding this correctly, but this seems to work fine to align the first partition, but what about my second partition? How do i align the second partition or is it automatically aligned?

    running joechang's script to verify sector alignment, i get the following after running the command above and creating a second partition right after the first.

    1st partition 32768, 17182609919
    2nd partition 17182609920, 36717649919


    As you can see, the first partition is aligned correctly:
    32768 / 512 = 64...so it aligns to the 64th sector

    but i dont understand about the 2nd partition...it doesn't seeem to align to a multiple of 32 or 64?
    17182609920 / 512 = 33559785....no way this number is a multiple of 32 or 64 or any even number for that matter


    Is diskpart only for aligning the first partition? And how can i align the following partitions if possible?

    XiNull
  2. joechang New Member

    it looks like your first partition is 16,386.61MB not 16,384
    hence the second partition was created immediately after the first
    instead of align on 32K or even 4K sectors

    try changing the size of the first or specify the start location of the second
  3. XiNull New Member

    Hmm,

    funny, dont know how that happened since my command line was <create partition primary align=32 size=16384>, hence 16384MB. It may have to do with this little text found on MS web site

    "The size is rounded to the closest cylinder boundary. For example, if you specify a size of 500 MB, the partition would be rounded up to 504 MB"

    Thanks, i had not noticed the size was not exactly 16GB. And i'll try again next week when i;m at the office.

    XiNull

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