在Exadata上为11.2.0.3 RAC配置Huge Page

在Exadata上为11.2.0.3 RAC配置Huge Page

1、如想设置SGA仅使用HugePage类型内存则设置：
Alter system set use_large_pages=ONLY scope=spfile;
否则可以保留use_large_pages=TRUE

2、 shutdown数据库实例

3、echo “vm.nr_hugepages=42000”   >>  /etc/sysctl.conf

4、sysctl -w vm.nr_hugepages=42000

5、grep Huge /proc/meminfo

如果grep Huge /proc/meminfo看到HugePages_Total不为42000，则需要重启OS才能使之生效

6、启动数据库实例

7、grep Huge /proc/meminfo

If the setting of nr_hugepages is not effective, you will need to reboot the server to make HugePages allocation during system startup.

[root@mac02db02 onecommand]#  dcli -g dbs_group -l “root” “egrep ‘HugePages_Free|HugePages_Total’ /proc/meminfo”
mac02db01: HugePages_Total:   42000
mac02db01: HugePages_Free:    29743
mac02db02: HugePages_Total:   42000
mac02db02: HugePages_Free:    35698
mac02db03: HugePages_Total:   42000
mac02db03: HugePages_Free:    35614
mac02db04: HugePages_Total:   42000
mac02db04: HugePages_Free:    35646

[root@mac02db02 onecommand]# dcli -g dbs_group -l “root” “grep ‘hugepage’ /etc/sysctl.conf| grep -v \#”
mac02db01: vm.nr_hugepages= 42000
mac02db02: vm.nr_hugepages= 42000
mac02db03: vm.nr_hugepages=42000
mac02db04: vm.nr_hugepages= 42000

show parameter db_name
col value for a10
col name for a20
select inst_id,NAME,VALUE from gv$parameter where name=’use_large_pages’;

SQL> show parameter instance_name

NAME                                 TYPE        VALUE
———————————— ———– ——————————
instance_name                        string      macdb2

select inst_id,NAME,VALUE from gv$parameter where name=’use_large_pages’;

  1* select inst_id,NAME,VALUE from gv$parameter where name=’use_large_pages’
SQL> /

   INST_ID NAME                 VALUE
———- ——————– ———-
         2 use_large_pages      ONLY
         1 use_large_pages      ONLY
         4 use_large_pages      ONLY
         3 use_large_pages      ONLY
     
     

    
SQL> SQL> col value for a10
SQL> select inst_id,NAME,VALUE from gv$parameter where name=’use_large_pages’;

   INST_ID NAME                 VALUE
———- ——————– ———-
         1 use_large_pages      ONLY
         2 use_large_pages      ONLY
         4 use_large_pages      ONLY
         3 use_large_pages      ONLY