centos7 oracle 12c 内存32G调整为16G

1. 32G oracle配置

1. 32G oracle配置

[oracle@oracle ~]$ sqlplus /nolog

SQL*Plus: Release 12.2.0.1.0 Production on Thu May 13 08:56:03 2021

Copyright (c) 1982, 2016, Oracle.  All rights reserved.

SQL> conn /as sysdba;
Connected.
SQL> show parameter sga;

NAME                     TYPE    VALUE
------------------------------------ ----------- ------------------------------
allow_group_access_to_sga        boolean     FALSE
lock_sga                 boolean     FALSE
pre_page_sga                 boolean     TRUE
sga_max_size                 big integer 9664M
sga_min_size                 big integer 0
sga_target               big integer 9664M
unified_audit_sga_queue_size         integer     1048576
SQL> 
SQL> show parameter pga;

NAME                     TYPE    VALUE
------------------------------------ ----------- ------------------------------
pga_aggregate_limit          big integer 6436M
pga_aggregate_target             big integer 3218M


SQL> show parameter target;      

NAME                     TYPE    VALUE
------------------------------------ ----------- ------------------------------
archive_lag_target           integer     0
db_big_table_cache_percent_target    string  0
db_flashback_retention_target        integer     1440
fast_start_io_target             integer     0
fast_start_mttr_target           integer     0
memory_max_target            big integer 0
memory_target                big integer 0
parallel_servers_target          integer     128
pga_aggregate_target             big integer 3218M
sga_target               big integer 9664M
target_pdbs              integer     0

2. 32G sysctl.conf配置

cat /etc/sysctl.conf 
fs.aio-max-nr = 1048576
fs.file-max = 6815744
kernel.shmall = 3294590
kernel.shmmax = 16868304896
kernel.shmmni= 4096
kernel.sem= 250 32000 100 128
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

3.16G oracle配置

SQL> show parameter sga;

NAME                     TYPE    VALUE
------------------------------------ ----------- ------------------------------
allow_group_access_to_sga        boolean     FALSE
lock_sga                 boolean     FALSE
pre_page_sga                 boolean     TRUE
sga_max_size                 big integer 8096M
sga_min_size                 big integer 0
sga_target               big integer 8000M
unified_audit_sga_queue_size         integer     1048576
SQL> 
SQL> show parameter pga;

NAME                     TYPE    VALUE
------------------------------------ ----------- ------------------------------
pga_aggregate_limit          big integer 2400M
pga_aggregate_target             big integer 798M


SQL> show parameter target;

NAME                     TYPE    VALUE
------------------------------------ ----------- ------------------------------
archive_lag_target           integer     0
db_big_table_cache_percent_target    string  0
db_flashback_retention_target        integer     1440
fast_start_io_target             integer     0
fast_start_mttr_target           integer     0
memory_max_target            big integer 0
memory_target                big integer 0
parallel_servers_target          integer     128
pga_aggregate_target             big integer 798M
sga_target               big integer 8000M
target_pdbs              integer     0

4. 16G sysctl.conf配置

cat /etc/sysctl.conf 
fs.aio-max-nr = 1048576
fs.file-max = 6815744
kernel.shmall = 2097152
kernel.shmmax = 4294967295
kernel.shmmni= 4096
kernel.sem= 250 32000 100 128
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

5. 修改32G oracle 的sysctl.conf

将
kernel.shmall = 3294590
kernel.shmmax = 16868304896
改为
kernel.shmall = 2097152
kernel.shmmax = 4294967295

执行命令使修改生效
sysctl -p

6. 修改32G oracle的配置

SQL> alter system set sga_max_size = 8096M scope=spfile;

System altered.

SQL> alter system set sga_target=8000M scope=spfile;

System altered.

SQL> alter system set pga_aggregate_target=798M scope=both;

System altered.

SQL> alter system set pga_aggregate_limit=2400M scope=both;

System altered.

7.重启oracle

>sqlplus /nolog
>conn /as sysdba

shutdown immediate;
startup;

8.修改服务器内存32G改为16G,然后启动oracle,已验证正常。