【大页内存】Oracle数据库配置大页内存

配置大页内存

脚本内容

1. #!/bin/bash
2. #
3. # hugepages_settings.sh
4. #
5. # Linux bash script to compute values for the
6. # recommended HugePages/HugeTLB configuration
7. # on Oracle Linux
8. #
9. # Note: This script does calculation for all shared memory
10. # segments available when the script is run, no matter it
11. # is an Oracle RDBMS shared memory segment or not.
12. #
13. # This script is provided by Doc ID 401749.1 from My Oracle Support
14. # http://support.oracle.com
16. # Welcome text
17. echo "
18. This script is provided by Doc ID 401749.1 from My Oracle Support
19. (http://support.oracle.com) where it is intended to compute values for
20. the recommended HugePages/HugeTLB configuration for the current shared
21. memory segments on Oracle Linux. Before proceeding with the execution please note following:
22. * For ASM instance, it needs to configure ASMM instead of AMM.
23. * The 'pga_aggregate_target' is outside the SGA and
24. you should accommodate this while calculating the overall size.
25. * In case you changes the DB SGA size,
26. as the new SGA will not fit in the previous HugePages configuration,
27. it had better disable the whole HugePages,
28. start the DB with new SGA size and run the script again.
29. And make sure that:
30. * Oracle Database instance(s) are up and running
31. * Oracle Database 11g Automatic Memory Management (AMM) is not setup
32. (See Doc ID 749851.1)
33. * The shared memory segments can be listed by command:
34. # ipcs -m
37. Press Enter to proceed..."
39. read
41. # Check for the kernel version
42. KERN=`uname -r | awk -F. '{ printf("%d.%d\n",$1,$2); }'`
44. # Find out the HugePage size
45. HPG_SZ=`grep Hugepagesize /proc/meminfo | awk '{print $2}'`
46. if [ -z "$HPG_SZ" ];then
47. echo "The hugepages may not be supported in the system where the script is being executed."
48. exit 1
49. fi
51. # Initialize the counter
52. NUM_PG=0
54. # Cumulative number of pages required to handle the running shared memory segments
55. for SEG_BYTES in `ipcs -m | cut -c44-300 | awk '{print $1}' | grep "[0-9][0-9]*"`
56. do
57. MIN_PG=`echo "$SEG_BYTES/($HPG_SZ*1024)" | bc -q`
58. if [ $MIN_PG -gt 0 ]; then
59. NUM_PG=`echo "$NUM_PG+$MIN_PG+1" | bc -q`
60. fi
61. done
63. RES_BYTES=`echo "$NUM_PG * $HPG_SZ * 1024" | bc -q`
65. # An SGA less than 100MB does not make sense
66. # Bail out if that is the case
67. if [ $RES_BYTES -lt 100000000 ]; then
68. echo "***********"
69. echo "** ERROR **"
70. echo "***********"
71. echo "Sorry! There are not enough total of shared memory segments allocated for
72. HugePages configuration. HugePages can only be used for shared memory segments
73. that you can list by command:
75. # ipcs -m
77. of a size that can match an Oracle Database SGA. Please make sure that:
78. * Oracle Database instance is up and running
79. * Oracle Database 11g Automatic Memory Management (AMM) is not configured"
80. exit 1
81. fi
83. # Finish with results
84. case $KERN in
85. '2.4') HUGETLB_POOL=`echo "$NUM_PG*$HPG_SZ/1024" | bc -q`;
86. echo "Recommended setting: vm.hugetlb_pool = $HUGETLB_POOL" ;;
87. '2.6') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
88. '3.8') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
89. '3.10') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
90. '4.1') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
91. '4.14') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
92. '4.18') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
93. '5.4') echo "Recommended setting: vm.nr_hugepages = $NUM_PG" ;;
94. *) echo "Kernel version $KERN is not supported by this script (yet). Exiting." ;;
95. esac
96. # End

开始配置

1. #运行,数据库开启状态
2. chmod +x hugepages_settings.sh
3. ./hugepages_settings.sh
5. # /etc/security/limits.conf 配置
6. * soft memlock 60397977
7. * hard memlock 60397977
9. #/etc/sysctl.conf 配置，eg
10. vm.nr_hugepages = 1496
11. sysctl -p
12. grep Huge /proc/meminfo
13. #重启数据库

当然也可以使用参数来锁定数据库使用的内存，以防止其他程序使用。如数据库参数use_large_pages。
系统参数vm.hugetlb_shm_group 。如调整该参数，请反复确认