Modify sysctl.conf for Oracle

mod_sysctl.sh

#!/bin/bash
#
# Change Linux kernel parameters prior to installing Oracle 11g R2 on RHEL 6.3
# v2.0 by [email protected] 2012.11.20
#


f='/etc/sysctl.conf'

# Get Total Memory in KB
memk=$(free|grep Mem|awk '{print$2}')

# Convert Memory to GB
memg=$(echo "$memk/1024/1024"|bc)

#Get page size
pagesizeb=$(getconf PAGE_SIZE)

# Calculate kernel.shmall and kernel.shmax
shmall=$(echo "$memg*1024^3/$pagesizeb"|bc)
shmmax=$(echo "$memg*1024^3/2"|bc)

## Calculate number of huge pages to allocate
hugepagesize=$(grep Hugepagesize /proc/meminfo|awk '{print$2}')

# create 1GB of huge pages
nr_hugepages=$(echo "1*1024^2/$hugepagesize"|bc)


## Begin making changes to sysctl.conf

# replace existing values for shmmall and shmax in sysctl.conf, and create bkup file
sed -i.bkup -e 's:\(kernel.shmmax = \)\([0-9]*\):\1'$shmmax':' \
  -e 's:\(kernel.shmall = \)\([0-9]*\):\1'$shmall':' $f

echo "

#### ORACLE Specific Info Below ####

kernel.shmmni = 4096

# semaphores: semmsl, semmns, semopm, semmni
kernel.sem = 250 32000 100 128

fs.file-max = 6815744
fs.aio-max-nr = 1048576

net.ipv4.ip_local_port_range = 9000 65500

net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 1048576

vm.swappiness = 0
vm.dirty_background_ration = 3
vm.dirty_ratio = 15
vm.dirty_expire_centisecs = 500
vm.dirty_writeback_centisecs = 100

vm.nr_hugepages = "$nr_hugepages >> $f