# 941735 - SAP memory management system for 64-bit Linux systems
# Description:    Recommendation for parameterization of 64-bit Linux systems.

[version]
VERSION=11
DATE=04.05.2018
DESCRIPTION=SAP memory management system for 64-bit Linux systems
REFERENCES=https://me.sap.com/notes/941735

[mem]
# /dev/shm
# With the STD implementation, the SAP Extended Memory is no longer stored in
# the TMPFS (under /dev/shm). However, the TMPFS is required by the Virtual
# Machine Container (VMC). For this reason, we still recommend the same
# configuration of the TMPFS:
# 75% (RAM + Swap) is still recommended as the size.

# use ShmFileSystemSizeMB to set an absolute value for your TMPFS
# if ShmFileSystemSizeMB is set to a value > 0, the setting for
# VSZ_TMPFS_PERCENT will be ignored and the size will NOT be calculated.
# if ShmFileSystemSizeMB is set to '0' the size will be calculated using
# VSZ_TMPFS_PERCENT
ShmFileSystemSizeMB=0

# Size of tmpfs mounted on /dev/shm in percent of the virtual memory.
# Depending on the size of the virtual memory (physical+swap) the
# value is calculated by (RAM + SWAP) * VSZ_TMPFS_PERCENT/100
# if VSZ_TMPFS_PERCENT is set to '0', the value is calculated by
# (RAM + SWAP) * 75/100
#
# Set to 75
# VSZ_TMPFS_PERCENT=75
#
VSZ_TMPFS_PERCENT=75

[sysctl]
# kernel.shmmax
# This value can be set the run time limit on the maximum shared memory
# segment size that can be created.
# see https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
# By default, the Linux distributions already set extremely large values 
# (SLES: 18446744073709551615); we recommend that you retain these unchanged.
#
kernel.shmmax=18446744073709551615

# kernel.shmall
# This parameter sets the total amount of shared memory pages that
# can be used system wide. Hence, SHMALL should always be at least
# ceil(shmmax/PAGE_SIZE).
# To determine the current page size run the command "getconf PAGE_SIZE".
# see https://www.kernel.org/doc/Documentation/sysctl/kernel.txt
# By default, the Linux distributions already set extremely large values 
# (SLES: 1152921504606846720); we recommend that you retain these unchanged.
#
kernel.shmall=1152921504606846720
