朋友在数据库软件从11.1.0.6升级到11.1.0.7后，发现数据库无法打开，不能继续下一步升级
数据库启动

SQL> startup upgrade
ORA-03113: end-of-file on communication channel

alert日志

Starting ORACLE instance (normal)
LICENSE_MAX_SESSION = 0
LICENSE_SESSIONS_WARNING = 0
Picked latch-free SCN scheme 3
Using LOG_ARCHIVE_DEST_10 parameter default value as USE_DB_RECOVERY_FILE_DEST
Autotune of undo retention is turned on.
IMODE=BR
ILAT =182
LICENSE_MAX_USERS = 0
SYS auditing is disabled
Starting up ORACLE RDBMS Version: 11.1.0.7.0.
Using parameter settings in server-side spfile /u01/app/oracle/product/11.1.0/db_1/dbs/spfilecenterdb.ora
System parameters with non-default values:
  processes                = 1500
  sessions                 = 1655
  memory_target            = 12864M
  control_files            = "/u01/app/oracle/oradata/centerdb/control01.ctl"
  control_files            = "/u01/app/oracle/oradata/centerdb/control02.ctl"
  control_files            = "/u01/app/oracle/oradata/centerdb/control03.ctl"
  db_block_size            = 8192
  compatible               = "11.1.0.0.0"
  db_recovery_file_dest    = "/u01/app/oracle/flash_recovery_area"
  db_recovery_file_dest_size= 2G
  undo_tablespace          = "UNDOTBS1"
  remote_login_passwordfile= "EXCLUSIVE"
  db_domain                = ""
  dispatchers              = "(PROTOCOL=TCP) (SERVICE=centerdbXDB)"
  audit_file_dest          = "/u01/app/oracle/admin/centerdb/adump"
  audit_trail              = "DB"
  db_name                  = "centerdb"
  open_cursors             = 300
  diagnostic_dest          = "/u01/app/oracle"
Thu Mar 29 15:47:06 2012
PMON started with pid=2, OS id=16324
Thu Mar 29 15:47:06 2012
VKTM started with pid=3, OS id=16326 at elevated priority
VKTM running at (20)ms precision
Thu Mar 29 15:47:06 2012
DIAG started with pid=4, OS id=16330
Thu Mar 29 15:47:06 2012
DBRM started with pid=5, OS id=16332
Thu Mar 29 15:47:06 2012
PSP0 started with pid=6, OS id=16334
Thu Mar 29 15:47:06 2012
DIA0 started with pid=7, OS id=16336
Thu Mar 29 15:47:06 2012
MMAN started with pid=8, OS id=16338
Thu Mar 29 15:47:06 2012
DBW0 started with pid=9, OS id=16340
Thu Mar 29 15:47:06 2012
DBW1 started with pid=10, OS id=16342
Thu Mar 29 15:47:06 2012
DBW2 started with pid=11, OS id=16344
Thu Mar 29 15:47:06 2012
DBW3 started with pid=12, OS id=16346
Thu Mar 29 15:47:06 2012
DBW4 started with pid=13, OS id=16348
Thu Mar 29 15:47:06 2012
DBW5 started with pid=14, OS id=16350
Thu Mar 29 15:47:06 2012
LGWR started with pid=15, OS id=16352
Thu Mar 29 15:47:06 2012
CKPT started with pid=16, OS id=16354
Thu Mar 29 15:47:06 2012
SMON started with pid=17, OS id=16356
Thu Mar 29 15:47:06 2012
RECO started with pid=18, OS id=16358
Thu Mar 29 15:47:06 2012
MMON started with pid=19, OS id=16360
starting up 1 dispatcher(s) for network address '(ADDRESS=(PARTIAL=YES)(PROTOCOL=TCP))'...
Thu Mar 29 15:47:06 2012
MMNL started with pid=20, OS id=16362
starting up 1 shared server(s) ...
Errors in file /u01/app/oracle/diag/rdbms/centerdb/centerdb/trace/centerdb_mman_16338.trc:
ORA-27103: internal error
Additional information: -1
Additional information: 1
MMAN (ospid: 16338): terminating the instance due to error 27103
Instance terminated by MMAN, pid = 16338

这里可以发现memory_target在12g以上

trace文件内容

[oracle@fcdb trace]$ more /u01/app/oracle/diag/rdbms/centerdb/centerdb/trace/centerdb_mman_16338.trc
Trace file /u01/app/oracle/diag/rdbms/centerdb/centerdb/trace/centerdb_mman_16338.trc
Oracle Database 11g Enterprise Edition Release 11.1.0.7.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
ORACLE_HOME = /u01/app/oracle/product/11.1.0/db_1
System name:    Linux
Node name:      fcdb
Release:        2.6.18-164.el5
Version:        #1 SMP Tue Aug 18 15:51:48 EDT 2009
Machine:        x86_64
Instance name: centerdb
Redo thread mounted by this instance: 0 <none>
Oracle process number: 8
Unix process pid: 16338, image: oracle@fcdb (MMAN)
*** 2012-03-29 15:47:06.865
*** SESSION ID:(1648.1) 2012-03-29 15:47:06.865
*** CLIENT ID:() 2012-03-29 15:47:06.865
*** SERVICE NAME:() 2012-03-29 15:47:06.865
*** MODULE NAME:() 2012-03-29 15:47:06.865
*** ACTION NAME:() 2012-03-29 15:47:06.865
error 27103 detected in background process
ORA-27103: internal error
Additional information: -1
Additional information: 1
*** 2012-03-29 15:47:06.865
MMAN (ospid: 16338): terminating the instance due to error 27103

结合alert和trace文件查询MOS，发现ORA-27103 when Memory target parameter is set to more than 3 GB [ID 743012.1]描述相符，是由于Bug:7272646引起.
鉴于朋友的数据库还升级过程中，所以给出的处理建议是先把memory_target改为2.8G，执行完升级操作，然后打上Patch:7272646
同时官方还给出了另一种解决方案:设置SHMMAX小于4G，个人不推荐；如果系统内存比较大，会出现多个内存段，影响系统性能