ITPub博客

首页 > Linux操作系统 > Linux操作系统 > linux oracle hugepages 配置和案例分析

linux oracle hugepages 配置和案例分析

原创 Linux操作系统 作者:hnhycwh 时间:2012-07-05 14:51:41 0 删除 编辑

一.系统当前状态

[root@node1 ora11g]#  cat /proc/meminfo | grep -i hugepages
HugePages_Total:     0
HugePages_Free:      0
HugePages_Rsvd:      0
Hugepagesize:     2048 kB
[root@node1 ora11g]# uname -sr
Linux 2.6.18-238.19.1.el5
cat /proc/meminfo|grep PageT
PageTables:      44748 kB
二.计算nr_hugepages值
#!/bin/bash
#
# hugepages_settings.sh
#
# Linux bash script. to compute values for the
# recommended HugePages/HugeTLB configuration
#
# Note: This script. does calculation for all shared memory
# segments available when the script. is run, no matter it
# is an Oracle RDBMS shared memory segment or not.
#
# This script. is provided by Doc ID 401749.1 from My Oracle Support
# http://support.oracle.com
  
# Welcome text
echo "
This script. is provided by Doc ID 401749.1 from My Oracle Support
(http://support.oracle.com) where it is intended to compute values for
the recommended HugePages/HugeTLB configuration for the current shared
memory segments. Before proceeding with the execution please make sure
that:
 * Oracle Database instance(s) are up and running
 * Oracle Database 11g Automatic Memory Management (AMM) is not setup
   (See Doc ID 749851.1)
 * The shared memory segments can be listed by command:
     # ipcs -m
  
Press Enter to proceed..."
  
read
  
# Check for the kernel version
KERN=`uname -r | awk -F. '{ printf("%d.%d\n",$1,$2); }'`
  
# Find out the HugePage size
HPG_SZ=`grep Hugepagesize /proc/meminfo | awk '{print $2}'`
  
# Initialize the counter
NUM_PG=0
  
# Cumulative number of pages required to handle the running shared memory segments
for SEG_BYTES in `ipcs -m | awk '{print $5}' | grep "[0-9][0-9]*"`
do
   MIN_PG=`echo "$SEG_BYTES/($HPG_SZ*1024)" | bc -q`
   if [ $MIN_PG -gt 0 ]; then
      NUM_PG=`echo "$NUM_PG+$MIN_PG+1" | bc -q`
   fi
done
  
RES_BYTES=`echo "$NUM_PG * $HPG_SZ * 1024" | bc -q`
  
# An SGA less than 100MB does not make sense
# Bail out if that is the case
if [ $RES_BYTES -lt 100000000 ]; then
   echo "***********"
   echo "** ERROR **"
   echo "***********"
   echo "Sorry! There are not enough total of shared memory segments allocated for
HugePages configuration. HugePages can only be used for shared memory segments
that you can list by command:
  
   # ipcs -m
  
of a size that can match an Oracle Database SGA. Please make sure that:
 * Oracle Database instance is up and running
 * Oracle Database 11g Automatic Memory Management (AMM) is not configured"
   exit 1
fi
  
# Finish with results
case $KERN in
   '2.4') HUGETLB_POOL=`echo "$NUM_PG*$HPG_SZ/1024" | bc -q`;
          echo "Recommended setting: vm.hugetlb_pool = $HUGETLB_POOL" ;;
   '2.6') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
    *) echo "Unrecognized kernel version $KERN. Exiting." ;;
esac
  
# End
三.修改系统配置
1./etc/sysctl.conf
vm.nr_hugepages = 770
  
2./etc/security/limits.conf
oracle soft memlock 102400
oracle hard memlock 102400
  
计算公式为:>=HugePages_Total*Hugepagesize

四.重启系统检查配置是否生效

[root@node1 ~]# cat /proc/meminfo | grep -i hugepages
HugePages_Total:   770
HugePages_Free:    770
HugePages_Rsvd:      0
Hugepagesize:     2048 kB
五.启动数据库并验证
[oracle@node1 ~]$ grep Huge /proc/meminfo
HugePages_Total:   770
HugePages_Free:    591
HugePages_Rsvd:    590
Hugepagesize:     2048 kB
[oracle@node1 ~]$ cat /proc/meminfo|grep PageT
PageTables:      13216 kB

HugePages_Free<>HugePages_Total,PageTables变小
证明HugePages配置成功

六.补充说明
1.在数据库内存服务器内存比较大的时候,可以考虑使用该功能,提高系统性能
2.对于Oracl 11g,如果需要使用此功能,需要关闭AMM功能(需要衡量)

 

转载http://www.xifenfei.com/2301.html

来自 “ ITPUB博客 ” ,链接:http://blog.itpub.net/27131216/viewspace-734668/,如需转载,请注明出处,否则将追究法律责任。

上一篇: 没有了~
请登录后发表评论 登录
全部评论

注册时间:2012-07-05

  • 博文量
    14
  • 访问量
    3403