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  1. RHEL
  2. RHEL-32124

tuned-profiles-sap needs an update for vm.max_map_count [RHEL 8]

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    • rhel-8.10.z
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    • tuned-2.22.1-4.el8_10.1
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      What were you trying to do that didn't work?

      Set the value for parameter vm.max_map_count to 2147483647 when switching to tuned profile sap-netweaver on a system which does not contain vm.max_map_count in a file in directory /etc/sysctl.d

      Please provide the package NVR for which bug is seen:

      tuned-profiles-sap-2.20.0-1.el8

      How reproducible:

      Always

      Steps to reproduce

      1. Ensure that the parameter vm.max_map_count is not in any file in /etc/sysctl.d:
      2. cd /etc/sysctl.d
      3. grep -rn vm.max_map_count
      4. echo $?
        1
      5. Install tuned-profiles-sap:
      6. dnf install tuned-profile-sap
      7. Switch to tuned profile sap-netweaver:
      8. tuned-adm profile sap-netweaver
      9. Display the value of vm.max_map_count:
      10. sysctl vm.max_map_count
        vm.max_map_count = 2000000

      Expected results

      According to applicable SAP notes for RHEL 8, vm.max_map_count is to be set to 2147483647. This is currently implemented in the RHEL System Roles for SAP for both RHEL releases, by configuring the file /etc/sysctl.d/sap.conf accordingly.

      But when using the tuned profile sap-netweaver and the parameter vm.max_map_count is not set in a flie in /etc/sysctl.d, the parameter vm.max_map_count also needs to be set to the correct value of 2147483647.

      So the tuned profile sap-netweaver needs to be updated from:

      vm.max_map_count = 2000000

      to:

      vm.max_map_count = 2147483647

      Actual results

      The file /usr/lib/tuned/sap-netweaver/tuned.conf contains in the [sysctl] section:
      vm.max_map_count = 2000000

      When running "tuned-adm profile sap-netweaver" for switching to this profile on a RHEL 9.2 system which has the file /etc/sysctl.d/sap.conf with the following line:
      vm.max_map_count=2147483647

      , the setting of vm.max_map_count will remain on the value of 2147483647, meaning it will not be lowered to 2000000.

      The corresponding entry in file /var/log/tuned/tuned.log is:

      2024-04-04 11:14:34,245 INFO     tuned.plugins.plugin_sysctl: Overriding sysctl parameter 'vm.max_map_count' from '2000000' to '2147483647'

      But when using the tuned profile sap-netweaver and the parameter vm.max_map_count is not set in a file in /etc/sysctl.d, the parameter vm.max_map_count will be set to the wrong value of 2000000.

              pzacik@redhat.com Pavol Zacik
              rhn-support-bfinger Bernd Finger
              Jaroslav Skarvada Jaroslav Skarvada
              Robin Hack Robin Hack
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                Created:
                Updated:
                Resolved: