Checking Page Fault Rates (UNIX) (SAP Library - SAP Memory Management (BC-CST-MM))

Checking Page Fault Rates (UNIX)

Prerequisites

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 performing system. The Pages out value is very important when assessing system performance.

Procedure

The following graphic displays the screen for transaction ST06. In the first screen, the current values for Pages in/s and Pages out/s are listed (in the following graphic under the heading Memory).

This graphic is explained in the accompanying text

To display the selection screen for more detailed information, choose Detail analysis menu. To get a list of the Pages in and Pages out values in the past 24 hours, in the block Previous hour choose Memory. The following screen displays this report.

This graphic is explained in the accompanying text

Caution

The following 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