一套Linux x86-64上的11.2.0.2数据库在startup启动阶段遭遇了ORA-27103:internal error内部错误，其出错日志如下: 
SQL> startup nomount;
ORA-27103: internal error
Linux-x86_64 Error: 2: No such file or directory
Additional information: 9404423
Additional information: 2

oerr 27103
Usage: oerr facility error

Facility is identified by the prefix string in the error message.
For example, if you get ORA-7300, "ora" is the facility and "7300"
is the error.  So you should type "oerr ora 7300".

If you get LCD-111, type "oerr lcd 111", and so on.

================= alert.log ====================
This instance was first to mount
2011-05-02 21:49:47.009000 +08:00
Use ADRCI or Support Workbench to package the incident.
See Note 411.1 at My Oracle Support for error and packaging details.
Errors in file /s01/orabase/diag/rdbms/prod/PROD1/trace/PROD1_asmb_14386.trc:
ORA-04031: unable to allocate 393240 bytes of shared memory
("large pool","unknown object","large pool","ASM map operations hashtable")
ASMB (ospid: 14386): terminating the instance due to error 4031

System state dump requested by (instance=1, osid=14386 (ASMB)), summary=[abnormal instance termination].

System State dumped to trace file /s01/orabase/diag/rdbms/prod/PROD1/trace/PROD1_diag_14346.trc

Dumping diagnostic data in directory=[cdmp_20110502214947], requested by
(instance=1, osid=14386 (ASMB)), summary=[abnormal instance termination].

Instance terminated by ASMB, pid = 14386

=============================system state dump============================

PROCESS 24: ASMB
  ----------------------------------------
  SO: 0x92c955c8, type: 2, owner: (nil), flag: INIT/-/-/0x00 if: 0x3 c: 0x3
   proc=0x92c955c8, name=process, file=ksu.h LINE:12451, pg=0
  (process) Oracle pid:24, ser:1, calls cur/top: 0x9288c778/0x9288c778
            flags : (0x6) SYSTEM
            flags2: (0x0),  flags3: (0x0)
            intr error: 0, call error: 0, sess error: 0, txn error 0
            intr queue: empty
    ksudlp FALSE at location: 0
  (post info) last post received: 2296 0 2
              last post received-location: ksl2.h LINE:2293 ID:kslpsr
              last process to post me: 92c8e248 1 6
              last post sent: 0 0 26
              last post sent-location: ksa2.h LINE:282 ID:ksasnd
              last process posted by me: 92c8e248 1 6
    (latch info) wait_event=0 bits=0
    Process Group: DEFAULT, pseudo proc: 0x92d24ae0
    O/S info: user: oracle, term: UNKNOWN, ospid: 14386
    OSD pid info: Unix process pid: 14386, image: oracle@rh2.oracle.com (ASMB)
    ----------------------------------------
    SO: 0x92e80a58, type: 4, owner: 0x92c955c8, flag: INIT/-/-/0x00 if: 0x3 c: 0x3
     proc=0x92c955c8, name=session, file=ksu.h LINE:12459, pg=0
    (session) sid: 13 ser: 1 trans: (nil), creator: 0x92c955c8
              flags: (0x51) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
              flags2: (0x408) -/-
              DID: , short-term DID:
              txn branch: (nil)
              oct: 0, prv: 0, sql: (nil), psql: (nil), user: 0/SYS
    ksuxds FALSE at location: 0
    service name: SYS$BACKGROUND
    Current Wait Stack:
      Not in wait; last wait ended 1.501399 sec ago
    Wait State:
      fixed_waits=0 flags=0x21 boundary=(nil)/-1
    Session Wait History:
        elapsed time of 1.501469 sec since last wait
     0: waited for 'SGA: allocation forcing component growth'
        =0x0, =0x0, =0x0
        wait_id=14 seq_num=27 snap_id=7
        wait times: snap=0.000000 sec, exc=0.305374 sec, total=0.305390 sec
        wait times: max=infinite
        wait counts: calls=6 os=6
        occurred after 0.000000 sec of elapsed time
     1: waited for 'SGA: allocation forcing component growth'
        =0x0, =0x0, =0x0
        wait_id=20 seq_num=26 snap_id=1
        wait times: snap=0.000001 sec, exc=0.000001 sec, total=0.000001 sec
        wait times: max=infinite
        wait counts: calls=1 os=1
        occurred after 0.000000 sec of elapsed time
     2: waited for 'SGA: allocation forcing component growth'
        =0x0, =0x0, =0x0
        wait_id=14 seq_num=25 snap_id=6
在没有阅读告警日志前我的第一反应可能是上次shutdown时Oracle进程没有被清理干净，导致shared memory segments一直没有释放，从而造成了以上ORA-27103错误。 不过其实这个问题告警日志里有明确的信息，即RDBMS Instance数据库实例在mount阶段asmb进程(负责db instance与asm instance的交互)试图从large pool大池中分配390k的空间，但遭遇了ORA-04031错误，如果asmb后台进程无法正常工作将直接导致db实例无法找到asm存储上的必要Extent，因此导致出出现了"ORA-27103: internal error:Linux-x86_64 Error: 2: No such file or directory"。 换而言之ORA-04031错误才是罪魁祸首，我们来是看该实例初始化的内存参数: 
[oracle@rh2 dbs]$ strings spfilePROD1.ora |egrep "sga|memory|pool"
PROD1.__large_pool_size=16777216
*.memory_target=943718400
*.shared_pool_size=314572800
*.streams_pool_size=0
因为是11g的实例所以采用了automatic memory management特性管理直接设置了memory_target参数为900M，并设置了1号实例的large pool最小为16M，900M的大小对于10g的实例而言仍是绰绰有余的，但是显然在11gr2中设置memory_target为900M是不足以驱动这样一个"庞然大物"的。我们需要配置更多的内存，亦或者可以通过设置更大的large pool来解决令人郁闷的ORA-04031错误: 
[oracle@rh2 dbs]$ strings spfilePROD1.ora > initPROD1.ora
[oracle@rh2 dbs]$ rm spfilePROD1.ora
[oracle@rh2 dbs]$ vi initPROD1.ora

/* 修改memory_target为至少912M */

*.memory_target=1200M


/* 成功启动!  */
SQL> startup ;
ORACLE instance started.

Total System Global Area 1252663296 bytes
Fixed Size                  2226072 bytes
Variable Size             687868008 bytes
Database Buffers          553648128 bytes
Redo Buffers                8921088 bytes
Database mounted.
Database opened.

Private Interface 'eth1:1' configured from GPnP for use as a private interconnect.
  [name='eth1:1', type=1, ip=169.254.236.169, mac=94-0c-6d-71-8c-c2, net=169.254.0.0/16, mask=255.255.0.0, use=haip:cluster_interconnect/62]
Public Interface 'eth0' configured from GPnP for use as a public interface.
  [name='eth0', type=1, ip=192.168.1.121, mac=6c-f0-49-03-5f-99, net=192.168.1.0/24, mask=255.255.255.0, use=public/1]
Public Interface 'eth0:1' configured from GPnP for use as a public interface.
  [name='eth0:1', type=1, ip=192.168.1.133, mac=6c-f0-49-03-5f-99, net=192.168.1.0/24, mask=255.255.255.0, use=public/1]
Public Interface 'eth0:2' configured from GPnP for use as a public interface.
  [name='eth0:2', type=1, ip=192.168.1.122, mac=6c-f0-49-03-5f-99, net=192.168.1.0/24, mask=255.255.255.0, use=public/1]
Picked latch-free SCN scheme 3
2011-05-02 22:28:04.408000 +08:00
WARNING: db_recovery_file_dest is same as db_create_file_dest
Autotune of undo retention is turned on.
LICENSE_MAX_USERS = 0
SYS auditing is disabled
Starting up:
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Partitioning, Real Application Clusters, OLAP, Data Mining
and Real Application Testing options.
Using parameter settings in server-side pfile /s01/oracle/product/11.2.0/dbhome_1/dbs/initPROD1.ora
System parameters with non-default values:
  processes                = 150
  shared_pool_size         = 304M
  streams_pool_size        = 0
  memory_target            = 1200M
  control_files            = "+DATA/prod/controlfile/current.261.747100215"
  control_files            = "+DATA/prod/controlfile/current.260.747100215"
  db_block_size            = 8192
  db_flash_cache_file      = "/flashcard/prod1cache.dsk"
  db_flash_cache_size      = 20G
  compatible               = "11.2.0.0.0"
  log_archive_dest_1       = "location=+DATA"
  cluster_database         = TRUE
  db_create_file_dest      = "+DATA"
  db_recovery_file_dest    = "+DATA"
  db_recovery_file_dest_size= 40320M
  thread                   = 1
  undo_tablespace          = "UNDOTBS1"
  instance_number          = 1
  db_domain                = ""
  dispatchers              = "(PROTOCOL=TCP) (SERVICE=PRODXDB)"
  remote_listener          = "rh-cluster-scan:1521"
  remote_listener          = "*.remote_login_pas"
  audit_file_dest          = "/s01/orabase/admin/PROD/adump"
  audit_trail              = "DB"
  db_name                  = "PROD"
  open_cursors             = 300
  diagnostic_dest          = "/s01/orabase"
Cluster communication is configured to use the following interface(s) for this instance
  169.254.236.169
cluster interconnect IPC version:Oracle UDP/IP (generic)
IPC Vendor 1 proto 2
2011-05-02 22:28:07.675000 +08:00
ORA-00132: syntax error or unresolved network name '*.remote_login_pas'
PMON started with pid=2, OS id=19807
PSP0 started with pid=3, OS id=19809
2011-05-02 22:28:08.754000 +08:00
VKTM started with pid=4, OS id=19811 at elevated priority
GEN0 started with pid=5, OS id=19815
VKTM running at (1)millisec precision with DBRM quantum (100)ms
DIAG started with pid=6, OS id=19817
DBRM started with pid=7, OS id=19819
PING started with pid=8, OS id=19821
ACMS started with pid=9, OS id=19823
DIA0 started with pid=10, OS id=19825
LMON started with pid=11, OS id=19827
LMD0 started with pid=12, OS id=19829
LMS0 started with pid=13, OS id=19831 at elevated priority
RMS0 started with pid=14, OS id=19835
LMHB started with pid=15, OS id=19837
MMAN started with pid=16, OS id=19839
* Load Monitor used for high load check
* New Low - High Load Threshold Range = [1920 - 2560]
LGWR started with pid=18, OS id=19843
DBW0 started with pid=17, OS id=19841
CKPT started with pid=19, OS id=19845
SMON started with pid=20, OS id=19847
RECO started with pid=21, OS id=19849
RBAL started with pid=22, OS id=19851
ASMB started with pid=23, OS id=19853 
MMON started with pid=24, OS id=19855
starting up 1 dispatcher(s) for network address '(ADDRESS=(PARTIAL=YES)(PROTOCOL=TCP))'...
MMNL started with pid=25, OS id=19857
starting up 1 shared server(s) ...
lmon registered with NM - instance number 1 (internal mem no 0)
2011-05-02 22:28:09.825000 +08:00
NOTE: initiating MARK startup
Starting background process MARK
MARK started with pid=28, OS id=19866
NOTE: MARK has subscribed
Reconfiguration started (old inc 0, new inc 2)
List of instances:
 1 (myinst: 1)
 Global Resource Directory frozen
* allocate domain 0, invalid = TRUE
 Communication channels reestablished
 Master broadcasted resource hash value bitmaps
 Non-local Process blocks cleaned out
 LMS 0: 0 GCS shadows cancelled, 0 closed, 0 Xw survived
 Set master node info
 Submitted all remote-enqueue requests
 Dwn-cvts replayed, VALBLKs dubious
 All grantable enqueues granted
 Post SMON to start 1st pass IR
 Submitted all GCS remote-cache requests
 Post SMON to start 1st pass IR
 Fix write in gcs resources
Reconfiguration complete
LCK0 started with pid=30, OS id=19872
Starting background process RSMN
RSMN started with pid=31, OS id=19874
ORACLE_BASE from environment = /s01/orabase
2011-05-02 22:28:12.112000 +08:00
ALTER DATABASE   MOUNT
This instance was first to mount
2011-05-02 22:28:13.202000 +08:00
NOTE: Loaded library: System
ALTER SYSTEM SET
local_listener='(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.1.122)(PORT=1521))))'
SCOPE=MEMORY SID='PROD1';
SUCCESS: diskgroup DATA was mounted
NOTE: dependency between database PROD and diskgroup resource ora.DATA.dg is established


/* 也可以直接增大large_pool_size来解决上述问题 */

large_pool_size=30M
memory_target=912M