[20170516]11G use_large_pages参数2.txt

[20170516]11G use_large_pages参数2.txt

//前面我提到如果设置use_large_pages=auto.设置页面大小不足时,oracle会oradism经常修改内核参数vm.nr_hugepages.
//忘记测试是否在退出后可以收回.链接如下:
http://blog.itpub.net/267265/viewspace-2135210/

--//不知道什么回事,以前写的,忘记发了,补上.

1.环境
SYS@book> @ &r/ver1

PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

SYS@book> show parameter  use_large_pages
NAME             TYPE     VALUE
---------------- -------- ------
use_large_pages  string   AUTO

--//重启数据库设置vm.nr_hugepages=100.执行sysctl -p.

# cat /proc/meminfo | grep -i  page
AnonPages:         63312 kB
PageTables:         2808 kB
AnonHugePages:         0 kB
HugePages_Total:     100
HugePages_Free:      100
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB

2.启动数据库:
SYS@book> startup
ORACLE instance started.

Total System Global Area  634732544 bytes
Fixed Size                  2255792 bytes
Variable Size             197133392 bytes
Database Buffers          427819008 bytes
Redo Buffers                7524352 bytes
Database mounted.
Database opened.

--//alert日志:
Tue May 16 15:37:05 2017
Adjusting the default value of parameter parallel_max_servers
from 480 to 120 due to the value of parameter processes (150)
Starting ORACLE instance (normal)
Specified value of sga_max_size is too small, bumping to 637534208
DISM started, OS id=42323
************************ Large Pages Information *******************
Parameter use_large_pages = AUTO
Per process system memlock (soft) limit = 51 GB

Total Shared Global Region in Large Pages = 610 MB (100%)

Large Pages used by this instance: 305 (610 MB)
Large Pages unused system wide = 0 (0 KB)
Large Pages configured system wide = 305 (610 MB)
Large Page size = 2048 KB
Time taken to allocate Large Pages = 0.015872 sec
********************************************************************

--//上次我提到建立进程42323,启动oradism修改内核参数.

# ps -p  42323 -l
F S   UID   PID  PPID  C PRI  NI ADDR SZ WCHAN  TTY          TIME CMD
4 S     0 42323     1  0  80   0 -  3338 pipe_w ?        00:00:00 oradism

$  ls -l $(which oradism)
-rwsr-x--- 1 root oinstall 71790 2013-08-24 10:51:02 /u01/app/oracle/product/11.2.0.4/dbhome_1/bin/oradism
--//oradism具有root属主.

# cat /proc/meminfo | grep -i  page
AnonPages:        157020 kB
PageTables:        11964 kB
AnonHugePages:         0 kB
HugePages_Total:     305
HugePages_Free:       99
HugePages_Rsvd:       99
HugePages_Surp:        0
Hugepagesize:       2048 kB

--//使用305.原来设置100不足.

3.测试关闭后是否会回收.
SYS@book> shutdown immediate ;
Database closed.
Database dismounted.
ORACLE instance shut down.

# cat /proc/meminfo | grep -i  page
AnonPages:         74060 kB
PageTables:         3856 kB
AnonHugePages:         0 kB
HugePages_Total:     305
HugePages_Free:      305
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB

--//可以发现不会回收.
# sysctl -p

# cat /proc/meminfo | grep -i  page
AnonPages:         73816 kB
PageTables:         3420 kB
AnonHugePages:         0 kB
HugePages_Total:     100
HugePages_Free:      100
HugePages_Rsvd:        0
HugePages_Surp:        0
Hugepagesize:       2048 kB

--//如果关闭数据库时能回收就好了.