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Memory Management, Pagefiles, Sections?

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The Question is:

In order to see what is going on, $INSTALL does provide some (incomplete)
 information about GBLPAGES. $INSTALL
L/G/SUMM does tell me gblpages in use/total and
the gblsections in use (omitting the number of total section available). The
 number of GBLSECTIONS can be found MCR SYSGEN show GBL*.
GBLPAGFIL is set to some value, how can I find out something about the actual
 usage in the running system of this value (to make sure the value is suffient
 and not excessive)?.
It would be very nice, if INSTALL could simply show all these values in the
 summary statement in a reasonable way.
winfried h. oppermann

The Answer is :

  INSTALL is the user command interface into the image activator,
  and is not particularly intended as a mechanism for monitoring
  system page file usage.  The mechanisms underneath INSTALL do use
  global sections and the global section system services, but these
  installed sections are typically file-backed sections, and not
  pagefile-backed sections.
  Global sections (created via INSTALL or via system service) will
  clearly use GBLPAGES and GBLSECTS, but the underlying page table
  data structures are small and thus reasonable overconfigurations
  of these parameters are not particularly wasteful of memory.
  The GBLPAGEFIL prevents excess use of the pagefile, but having
  sufficient pagefile configured is also not particularly wasteful
  of resources given the current costs of large-scale disk storage.
  For information on the system configuration, please see the $getsyi
  service (or f$getsyi lexical) and FREE_GBLPAGES, CONTIG_GBLPAGES,
  In the specific case of the GBLPAGFIL parameter, this is a dynamic
  parameter that controls the amount of pagefile that can be allocated
  for use as backing storage for global sections, meaning that the
  PAGEFILE_FREE and PAGEFILE_PAGE parameters would be among the most
  interesting, as well as (obviously) the DCL command SHOW MEMORY.
  If you wish to reduce the amount of storage used in the pagefile,
  you can use file-backed sections.
  Some of the related topics include (7752), (6536), and (5002).

answer written or last revised on ( 10-JUL-2002 )

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