ORA-27123: unable to attach to shared memory segment

[oracle@ebus ~]$ . /disk2/PROD11/prod11db/9.2.0/PROD11_ebus.env

[oracle@ebus bin]$ sqlplus "/as sysdba"

SQL*Plus: Release 9.2.0.5.0 - Production on Thu Feb 16 11:33:30 2012

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

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: 950286
SQL> exit
Disconnected
Alert Log Error :-

WARNING: EINVAL creating segment of size 0x0000000081c00000
fix shm parameters in /etc/system or equivalent
Wed Feb 15 13:37:48 2012
Starting ORACLE instance (normal)
Wed Feb 15 13:37:48 2012
WARNING: EINVAL creating segment of size 0x0000000081c00000
fix shm parameters in /etc/system or equivalent
Wed Feb 15 13:38:31 2012
Starting ORACLE instance (normal)
Wed Feb 15 13:38:31 2012
WARNING: EINVAL creating segment of size 0x0000000081c00000
fix shm parameters in /etc/system or equivalent
Wed Feb 15 13:40:07 2012
Starting ORACLE instance (normal)
Wed Feb 15 13:40:07 2012
WARNING: EINVAL creating segment of size 0x0000000081c00000
fix shm parameters in /etc/system or equivalent
Wed Feb 15 13:44:42 2012
Starting ORACLE instance (normal)
Wed Feb 15 13:44:42 2012

[oracle@ebus bin]$ $ORACLE_HOME/bin/genksms -b 0x80000000 >ksms.s
[oracle@ebus bin]$ cd $ORACLE_HOME/rdbms/lib
[oracle@ebus lib]$ $ORACLE_HOME/bin/genksms -b 0x80000000 >ksms.s
[oracle@ebus lib]$ make -f ins_rdbms.mk ksms.o
[oracle@ebus lib]$ ar r $ORACLE_HOME/lib/libserver9.a ksms.o
[oracle@ebus lib]$ make -f ins_rdbms.mk ioracle

 - Linking Oracle
rm -f /disk2/PROD11/prod11db/9.2.0/rdbms/lib/oracle
gcc  -o /disk2/PROD11/prod11db/9.2.0/rdbms/lib/oracle -L/disk2/PROD11/prod11db/9                                                                                        .2.0/rdbms/lib/ -L/disk2/PROD11/prod11db/9.2.0/lib/ -L/disk2/PROD11/prod11db/9.2                                                                                        .0/lib/stubs/   -Wl,-E `test -f /disk2/PROD11/prod11db/9.2.0/rdbms/lib/skgaioi.o                                                                                         && echo /disk2/PROD11/prod11db/9.2.0/rdbms/lib/skgaioi.o` /disk2/PROD11/prod11d                                                                                        b/9.2.0/rdbms/lib/opimai.o /disk2/PROD11/prod11db/9.2.0/rdbms/lib/ssoraed.o /dis                                                                                        k2/PROD11/prod11db/9.2.0/rdbms/lib/ttcsoi.o /disk2/PROD11/prod11db/9.2.0/lib/nau                                                                                        tab.o /disk2/PROD11/prod11db/9.2.0/lib/naeet.o /disk2/PROD11/prod11db/9.2.0/lib/                                                                                        naect.o /disk2/PROD11/prod11db/9.2.0/lib/naedhs.o /disk2/PROD11/prod11db/9.2.0/r                                                                                        dbms/lib/config.o  -lserver9 -lodm9 -lskgxp9 -lskgxn9 -lclient9  -lvsn9 -lwtcser                                                                                        ver9 -lcommon9 -lgeneric9 /disk2/PROD11/prod11db/9.2.0/rdbms/lib/defopt.o -lknlo                                                                                        pt `if /usr/bin/ar tv /disk2/PROD11/prod11db/9.2.0/rdbms/lib/libknlopt.a | grep                                                                                         xsyeolap.o > /dev/null 2>&1 ; then echo "-loraolap9" ; fi`  -lslax9 -lpls9  -lpl                                                                                        p9 -lserver9 -lclient9  -lvsn9 -lwtcserver9 -lcommon9 -lgeneric9 -lknlopt -lslax                                                                                        9 -lpls9  -lplp9 -ljox9 -lserver9 -locijdbcst9 -lwwg9  `cat /disk2/PROD11/prod11                                                                                        db/9.2.0/lib/ldflags`    -lnsslb9 -lncrypt9 -lnsgr9 -lnzjs9 -ln9 -lnl9 -lnro9 `c                                                                                        at /disk2/PROD11/prod11db/9.2.0/lib/ldflags`    -lnsslb9 -lncrypt9 -lnsgr9 -lnzj                                                                                        s9 -ln9 -lnl9 -lmm -lnls9  -lcore9 -lnls9 -lcore9 -lnls9 -lxml9 -lcore9 -lunls9                                                                                         -lnls9 `cat /disk2/PROD11/prod11db/9.2.0/lib/ldflags`    -lnsslb9 -lncrypt9 -lns                                                                                        gr9 -lnzjs9 -ln9 -lnl9 -lnro9 `cat /disk2/PROD11/prod11db/9.2.0/lib/ldflags`                                                                                            -lnsslb9 -lncrypt9 -lnsgr9 -lnzjs9 -ln9 -lnl9  -ltrace9 -lnls9  -lcore9 -lnls9 -                                                                                        lcore9 -lnls9 -lxml9 -lcore9 -lunls9 -lnls9 `if /usr/bin/ar tv /disk2/PROD11/pro                                                                                        d11db/9.2.0/rdbms/lib/libknlopt.a | grep "kxmnsd.o" > /dev/null 2>&1 ; then echo                                                                                         " " ; else echo "-lordsdo9"; fi` -lctxc9 -lctx9 -lzx9 -lgx9 -lctx9 -lzx9 -lgx9                                                                                         -lordimt9 -lnls9  -lcore9 -lnls9 -lcore9 -lnls9 -lxml9 -lcore9 -lunls9 -lnls9 -l                                                                                        snls9 -lunls9 -lxsd9 -lnls9  -lcore9 -lnls9 -lcore9 -lnls9 -lxml9 -lcore9 -lunls                                                                                        9 -lnls9   `cat /disk2/PROD11/prod11db/9.2.0/lib/sysliblist` -Wl,-rpath,/disk2/P                                                                                        ROD11/prod11db/9.2.0/lib:/lib:/usr/lib -lm    `cat /disk2/PROD11/prod11db/9.2.0/                                                                                        lib/sysliblist` -ldl -lm   `test -f /disk2/PROD11/prod11db/9.2.0/rdbms/lib/skgai                                                                                        oi.o && echo -laio`
mv -f /disk2/PROD11/prod11db/9.2.0/bin/oracle /disk2/PROD11/prod11db/9.2.0/bin/o
mv /disk2/PROD11/prod11db/9.2.0/rdbms/lib/oracle /disk2/PROD11/prod11db/9.2.0/bi
chmod 6751 /disk2/PROD11/prod11db/9.2.0/bin/oracle
[oracle@ebus lib]$ sqlplus "/as sysdba"

SQL*Plus: Release 9.2.0.5.0 - Production on Thu Feb 16 11:35:57 2012

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

Connected to an idle instance.

SQL> startup
ORACLE instance started.

Total System Global Area  581506616 bytes
Fixed Size                   452152 bytes
Variable Size             402653184 bytes
Database Buffers          167772160 bytes
Redo Buffers               10629120 bytes
Database mounted.
Database opened.
SQL> exit
Disconnected from Oracle9i Enterprise Edition Release 9.2.0.5.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.5.0 - Production
[oracle@ebus lib]$


Reference Metalink note Number :- How to Relocate the SGA (By Changing the SGABEG Parameter) [ID 1028623.6]