Calculating disk space

• tmmutsetse

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  June 6, 2016 at 6:41 am

  #308168

  Good day experts,

  I am going through some sql queries on my envronment.There is this query below which calculates disk space.I just want to know that why do we have to use /1024 three times.

  Select left(Volumedescription,1) as driveName,

  cast(cast(Volumesize as numeric(20,2))/1024/1024/1024 as numeric(13,2)) as TotalSpace,

  cast(cast(VolumeSpaceAvailable as numeric(20,2))/1024/1024/1024 as numeric(13,2)) as FreeSpace.

  I am new to sql.

  Thanks in advance

• kreuzer

  Ten Centuries

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  June 6, 2016 at 6:48 am

  #1883342

  Hi,

  I don't know the source of your query, but if you got bytes, you had to divide 3 time

  Bytes / 1024 = KB

  KB / 1014 = MB

  MB / 1024 = GB

  Regards,

  Andreas

• tmmutsetse

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  June 6, 2016 at 6:55 am

  #1883344

  Thank you .Now i know

• Eirikur Eiriksson

  SSC Guru

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  June 6, 2016 at 7:14 am

  #1883348

  Piling on, here is an easy way to remember this

  😎

  DECLARE @X_BYTES BIGINT = 10240000000000;

  SELECT

  @X_BYTES / POWER(CONVERT(BIGINT,2,0),10) AS KILO_BITES

  ,@X_BYTES / POWER(CONVERT(BIGINT,2,0),20) AS MEGA_BITES

  ,@X_BYTES / POWER(CONVERT(BIGINT,2,0),30) AS GIGA_BITES

  ,@X_BYTES / POWER(CONVERT(BIGINT,2,0),40) AS TERA_BITES

  ;