Checking Page Fault Rates (UNIX)

Context

Unlike Windows, pages are swapped out to the working memory under UNIX if the space is needed, and then they are overwritten. This swapping out uses up valuable time and performance.

Transaction ST06 displays a small [Pages out] value and a similar [Pages in] value in a system with high performance. The [Pages out] value is very important when assessing system performance.

The following limit values for [Pages in] should not be exceeded in the short or long term.

Value Limit: Pages out under UNIX

Pages Out

Value Limit

Short-term maximum for [Pages out]/s

200

Long-term maximum for [Pages out]/h

600.000

Procedure

  1. Call transaction ST06. The first screen contains the current values for [Pages in]/s and [Pages out]/s under Memory.
  2. Choose the following menu path to access the detailed analysis: Start of the navigation pathEnvironment Next navigation step ST06 OldEnd of the navigation path.
  3. To display the selection screen for more detailed information, choose Detail analysis menu.
  4. By choosing Memory in block Previous 24 Hours, a list of [Pages in] and [Pages out] values in the preceeding 24 hours is displayed.