linux7.4开启hugepages
环境检查
数据库内存超过4G时，使用dbca建库默认选项AMM是关闭的，内存超过8G时，oracle推荐使用hugepages，它可以将部分数据锁定在内存中，处理效率比较高、性能好。
确认服务器物理内存已经超过8G，是大内存
确认数据库实例没有使用AMM，hugepages与AMM不同时使用
Memlock
如果/etc/security/limits.d/*.conf中没有关于memlock参数的设置，那么
memlock的值介于SGA与物理内存之间，比SGA大，比物理内存小
推荐值SGA+PGA为物理内存80%，memlock为物理内存90%
Memlock = 物理内存*90%*1024*1024
vim /etc/security/limits.conf
oracle soft memlock 237363200
oracle hard memlock 237363200
# su - oracle
$ ulimit -l
237363200
脚本获取推荐值
chmod +x hugepages_settings.sh
[root@crcsn1 scripts]# ./hugepages_settings.sh
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 on Oracle Linux. Before proceeding with the execution please note following:
* For ASM instance, it needs to configure ASMM instead of AMM.
* The 'pga_aggregate_target' is outside the SGA and
you should accommodate this while calculating SGA size.
* In case you changes the DB SGA size,
as the new SGA will not fit in the previous HugePages configuration,
it had better disable the whole HugePages,
start the DB with new SGA size and run the script again.
And 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...
Recommended setting: vm.nr_hugepages = 72708
[root@crcsn1 scripts]# ipcs -m
------ Shared Memory Segments --------
key shmid owner perms bytes nattch status
0x00000000 1245184 grid 600 4096 0
0x00000000 1277953 grid 600 4096 0
0x4dfc72ac 1310722 grid 600 24576 48
0x00000000 1343491 grid 600 8802304 124
0x00000000 1376260 grid 600 1056964608 62
0x00000000 1409029 grid 600 7974912 62
0xef940690 1441798 grid 600 20480 62
0x00000000 2129927 oracle 600 30035968 614
0x00000000 2162696 oracle 600 150860726272 307
0x00000000 2195465 oracle 600 506834944 307
0x51c60604 2228234 oracle 600 24576 307
设置hugepages
# vim /etc/sysctl.conf
vm.nr_hugepages = 72708
# sysctl -p
# grep HugePages /proc/meminfo
AnonHugePages: 1093632 kB
HugePages_Total: 61313
HugePages_Free: 61313
HugePages_Rsvd: 0
HugePages_Surp: 0
附件
hugepages_settings.sh
|
#!/bin/bash # # hugepages_settings.sh # # Linux bash script to compute values for the # recommended HugePages/HugeTLB configuration # on Oracle Linux # # 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 on Oracle Linux. Before proceeding with the execution please note following: * For ASM instance, it needs to configure ASMM instead of AMM. * The 'pga_aggregate_target' is outside the SGA and you should accommodate this while calculating SGA size. * In case you changes the DB SGA size, as the new SGA will not fit in the previous HugePages configuration, it had better disable the whole HugePages, start the DB with new SGA size and run the script again. And 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); }'` ...skipping... for SEG_BYTES in `ipcs -m | cut -c44-300 | awk '{print $1}' | grep "[0-9][0-9]*"` do MIN_PG=`echo "$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 '2.2') echo "Kernel version $KERN is not supported. Exiting." ;; '2.4') HUGETLB_POOL=`echo "$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" ;; '3.8') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; '3.10') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; '4.1') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;; esac
# End |
参考
- HugePages on Oracle Linux 64-bit (文档 ID 361468.1)
- Oracle Linux: Shell Script to Calculate Values Recommended Linux HugePages / HugeTLB Configuration (文档 ID 401749.1)
