如何解決ORA-00845錯誤

今天剛剛安裝了一個oracle 11gr2的資料庫，第一次啟動時報 ORA-00845錯誤。

[email protected]:/home/oracle>sqlplus "/as sysdba"

SQL*Plus: Release 11.2.0.2.0 Production on Fri Apr 15 16:08:57 2011

Copyright (c) 1982, 2010, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup

ORA-00845: MEMORY_TARGET not supported on this system

SQL> exit

Disconnected

檢視資料：

Starting with Oracle Database 11g, the Automatic Memory Management feature requires more shared memory (/dev/shm)and file descriptors.

The size of the shared memory should be at least the greater of MEMORY_MAX_TARGET and MEMORY_TARGET for each Oracle instance on the computer. If MEMORY_MAX_TARGET or MEMORY_TARGET is set to a non zero value, and an incorrect size is assigned to the shared memory,

it will result in an ORA-00845 error at startup.

問題是由于設定SGA的大小超過了作業系統/dev/shm的大小：

[email protected]:/home/oracle>df -h /dev/shm          

Filesystem            Size  Used Avail Use% Mounted on

tmpfs                  71G   34G   37G  48% /dev/shm

可用大小是37G 而從spfile檔案裡的memory_target 是50 多G .

SQL*Plus: Release 11.2.0.2.0 Production on Fri Apr 15 16:13:44 2011

SQL> create pfile='/tmp/orcl.ora' from spfile;

File created.

[email protected]:/home/oracle>vim  /tmp/orcl.ora

orcl.__db_cache_size=32346472448

orcl.__java_pool_size=134217728

orcl.__large_pool_size=134217728

orcl.__oracle_base='/apsarapangu/disk1/opt/oracle'#ORACLE_BASE set from environment

orcl.__pga_aggregate_target=24427626496

orcl.__sga_target=36373004288

orcl.__shared_io_pool_size=0

orcl.__shared_pool_size=3221225472

orcl.__streams_pool_size=134217728

*.audit_file_dest='/apsarapangu/disk1/opt/oracle/admin/orcl/adump'

*.audit_trail='db'

*.compatible='11.2.0.0.0'

*.control_files='/apsarapangu/disk1/opt/oracle/oradata/orcl/control01.ctl','/apsarapangu/disk1/opt/oracle/fast_recovery_

area/orcl/control02.ctl'

*.db_block_size=8192

*.db_domain='yh.com'

*.db_name='orcl'

*.db_recovery_file_dest='/apsarapangu/disk1/opt/oracle/fast_recovery_area'

*.db_recovery_file_dest_size=4227858432

*.diagnostic_dest='/apsarapangu/disk1/opt/oracle'

*.dispatchers='(PROTOCOL=TCP) (SERVICE=orclXDB)'

#*.memory_target=60800630784 大于可用/dev/shm大小。将其修改為16g。

*.memory_target=17179869184

*.open_cursors=300

*.processes=150

*.remote_login_passwordfile='EXCLUSIVE'

*.undo_tablespace='UNDOTBS1'                                          

"/tmp/orcl.ora" 26L, 1049C written  

重新啟動。

SQL*Plus: Release 11.2.0.2.0 Production on Fri Apr 15 16:30:16 2011

SQL> startup pfile='/tmp/orcl.ora'

ORACLE instance started.

Total System Global Area 1.7103E+10 bytes

Fixed Size                  2243608 bytes

Variable Size            8455717864 bytes

Database Buffers         8623489024 bytes

Redo Buffers               21712896 bytes

Database mounted.

Database opened.

==============================

當然可以修改/dev/shm大小 ，使其大于SGA大小。

解決步驟：

修改/etc/fstab 中/dev/shm 的大小，使其大于SGA 的大小。

#vi /etc/fstab

LABEL=/ / ext3 defaults 1 1

LABEL=/boot /boot ext3 defaults 1 2

LABEL=/data /data ext3 defaults 1 2

devpts /dev/pts devpts gid=5,mode=620 0 0

#tmpfs /dev/shm tmpfs defaults 0 0

tmpfs /dev/shm tmpfs defaults,size=10240M 0 0

。。。。

LABEL=SWAP-sda swap swap defaults 0 0

~

"/etc/fstab" 13L, 965C written

解除安裝再加載

# umount /dev/shm

# mount /dev/shm

再次檢視。

# df -k /dev/shm