如何在Linux上扩展SGA超过1.7G

王朝system·作者佚名 2008-05-19

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今天一台Linux服务器扩展了一下内存,达到4G,开发的人自己修改了一下SGA结果数据库无法启动了.

启动不了时,出的错误是这个样子的:

[oracle@neirong oracle]$ sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.4.0 - Production on Fri Nov 25 15:43:26 2005

Connected to an idle instance.

SQL startup

ORA-27123: unable to attach to shared memory segment

Linux Error: 22: Invalid argument

Additional information: 1

Additional information: 458753

SQL exit

Disconnected

在32位平台上,缺省的SGA最大只能扩展到1.7G,如果需要支持更大的内存,就需要降低mapped_base,重新Link Oracle软件.

俺的平台为:

[oracle@neirong bdump]$ cat /etc/redhat-release

Red Hat Enterprise Linux AS release 3 (Taroon Update 2)

简单操作如下:

cd $ORACLE_HOME/rdbms/lib

cp ksms.s ksms.s.bak

genksms -s 0x12000000 ksms.s

make -f ins_rdbms.mk ksms.o

make -f ins_rdbms.mk ioracle

此处先备份ksms.s文件,如果编译过程中出现错误,保证操作可以被恢复:

恢复步骤大致如下:

cd $ORACLE_HOME/rdbms/lib

cp ksms.s.bak ksms.s

genksms ksms.s

make -f ins_rdbms.mk ksms.o

make -f ins_rdbms.mk ioracle

以下是操作日志:

[oracle@neirong dbs]$ cd $ORACLE_HOME/rdbms/lib

[oracle@neirong lib]$ genksms -s 0x12000000 ksms.s

[oracle@neirong lib]$ make -f ins_rdbms.mk ksms.o

[oracle@neirong lib]$ make -f ins_rdbms.mk ioracle

- Linking Oracle

rm -f /opt/oracle/product/9.2.0/rdbms/lib/oracle

gcc

-o /opt/oracle/product/9.2.0/rdbms/lib/oracle -L/opt/oracle/product/9.2.0/rdbms/lib/

-L/opt/oracle/product/9.2.0/lib/ -L/opt/oracle/product/9.2.0/lib/stubs/

-Wl,-E `test -f /opt/oracle/product/9.2.0/rdbms/lib/skgaioi.o && echo

/opt/oracle/product/9.2.0/rdbms/lib/skgaioi.o` /opt/oracle/product/9.2.0/rdbms/lib/opimai.o

/opt/oracle/product/9.2.0/rdbms/lib/ssoraed.o /opt/oracle/product/9.2.0/rdbms/lib/ttcsoi.o

/opt/oracle/product/9.2.0/lib/nautab.o /opt/oracle/product/9.2.0/lib/naeet.o

/opt/oracle/product/9.2.0/lib/naect.o /opt/oracle/product/9.2.0/lib/naedhs.o

/opt/oracle/product/9.2.0/rdbms/lib/config.o

-lserver9 -lodm9 -lskgxp9 -lskgxn9 -lclient9

-lvsn9 -lwtcserver9 -lcommon9 -lgeneric9 /opt/oracle/product/9.2.0/rdbms/lib/defopt.o

-lknlopt `if /usr/bin/ar tv /opt/oracle/product/9.2.0/rdbms/lib/libknlopt.a | grep

xsyeolap.o /dev/null 2&1 ; then echo "-loraolap9" ; fi`

-lslax9 -lpls9

-lplp9 -lserver9 -lclient9

-lvsn9 -lwtcserver9 -lcommon9 -lgeneric9

-lknlopt -lslax9 -lpls9

-lplp9 -ljox9 -lserver9 -locijdbcst9 -lwwg9

`cat /opt/oracle/product/9.2.0/lib/ldflags`

-lnsslb9 -lncrypt9 -lnsgr9 -lnzjs9

-ln9 -lnl9 -lnro9 `cat /opt/oracle/product/9.2.0/lib/ldflags`

-lnsslb9 -lncrypt9

......

mv -f /opt/oracle/product/9.2.0/bin/oracle /opt/oracle/product/9.2.0/bin/oracleO

mv /opt/oracle/product/9.2.0/rdbms/lib/oracle /opt/oracle/product/9.2.0/bin/oracle

chmod 6751 /opt/oracle/product/9.2.0/bin/oracle

此后数据库可以以超过1.7G的SGA区设置启动:

SQL startup

ORACLE instance started.

Total System Global Area 2685476820 bytes

Fixed Size

454612 bytes

Variable Size

1073741824 bytes

Database Buffers

1610612736 bytes

Redo Buffers

667648 bytes

Database mounted.

Database opened.