ORA-00845 和 ORA-01102案例
表象
oracle@mmsg01:/home> sqlplus "/ as sysdba"
SQL*Plus: Release 11.1.0.7.0 - Production on Tue Mar 23 17:55:21 2010
Copyright (c) 1982, 2008, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup
ORA-00845: MEMORY_TARGET not supported on this system
SQL> exit
Disconnected
oracle@mmsg01:/home> oerr ora 00845
00845, 00000, "MEMORY_TARGET not supported on this system"
// *Cause: The MEMORY_TARGET parameter was not supported on this operating system or /dev/shm was not sized correctly on Linux.
// *Action: Refer to documentation for a list of supported operating systems. Or, size /dev/shm to be at least the SGA_MAX_SIZE on each Oracle instance running on the system.
oracle@mmsg01:/home>
原因
这个问题是由于设置SGA的大小超过了操作系统/dev/shm的大小：
解决方法
解决这个问题只有两个方法：
一是修改初始化参数，使得初始化参数中SGA的设置小于/dev/shm的大小；
二是调整/dev/shm的大小。
修改/dev/shm的大小可以通过修改/etc/fstab来实现
mmsg01:/etc/init.d # df -k /dev/shm
Filesystem 1K-blocks Used Available Use% Mounted on
shmfs 4194304 0 4194304 0% /dev/shm
vi /etc/fstab
mmsg01:/etc/init.d # vi /etc/fstab
/dev/disk/by-id/scsi-3600508e000000000da19d06c68ac5e0b-part2 / reiserfs acl,user_xattr 1 1
/dev/disk/by-id/scsi-3600508e000000000da19d06c68ac5e0b-part5 /home reiserfs acl,user_xattr 1 2
/dev/disk/by-id/scsi-3600508e000000000da19d06c68ac5e0b-part1 swap swap defaults 0 0
proc /proc proc defaults 0 0
sysfs /sys sysfs noauto 0 0
debugfs /sys/kernel/debug debugfs noauto 0 0
usbfs /proc/bus/usb usbfs noauto 0 0
devpts /dev/pts devpts mode=0620,gid=5 0 0
shm /dev/shm tmpfs size=8g 0 0
＃shmfs /dev/shm tmpfs size=4g 0
shmfs /dev/shm tmpfs size=8g 0 #新增加的一行
解邦
umount /dev/shm
重新邦定
mount /dev/shm
查看邦定结果
df -k
mmsg01:/etc/init.d # df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sda2 41944376 4417892 37526484 11% /
udev 8218880 240 8218640 1% /dev
/dev/sda5 73398648 15426492 57972156 22% /home
shm 8388608 0 8388608 0% /dev/shm
启动数据库
oracle@mmsg01:~/oradata/mmsgdb> sqlplus / as sysdba
SQL*Plus: Release 11.1.0.7.0 - Production on Tue Mar 23 20:33:20 2010
Copyright (c) 1982, 2008, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup
ORA-00845: MEMORY_TARGET not supported on this system
SQL> startup
ORA-00845: MEMORY_TARGET not supported on this system
SQL> startup
ORACLE instance started.
Total System Global Area 8417955840 bytes
Fixed Size 2161312 bytes
Variable Size 4429186400 bytes
Database Buffers 3959422976 bytes
Redo Buffers 27185152 bytes
ORA-01102: cannot mount database in EXCLUSIVE mode
SQL>
出现了另外一个错误：ORA-01102
这个错误主要是lk
说明DATABASE MOUNT上了,不用再去MOUNT了。
具体解决ORA-01102问题的步骤：
oracle@mmsg01:~/product/11g/dbs> /sbin/fuser -u lkMMSGDB
lkMMSGDB: 24500(oracle) 24508(oracle) 24510(oracle) 24514(oracle) 24516(oracle) 24518(oracle) 24520(oracle) 24522(oracle) 24524(oracle) 24526(oracle) 24528(oracle) 24585(oracle) 24589(oracle) 24667(oracle) 24669(oracle) 24693(oracle)
发现lkMMSGDB文件没有释放，使用fuser命令kill掉lkMMSGDB
oracle@mmsg01:~/product/11g/dbs> /sbin/fuser -k lkMMSGDB
lkMMSGDB: 24500 24508 24510 24514 24516 24518 24520 24522 24524 24526 24528 24585 24589 24667 24669 24693
再去检查lkMMSGDB文件是否释放
oracle@mmsg01:~/product/11g/dbs> /sbin/fuser -u lkMMSGDB
不显示任何信息，说明lkMMSGDB文件已经释放
重新启动数据库
oracle@mmsg01:~/product/11g/dbs> sqlplus / as sysdba
SQL*Plus: Release 11.1.0.7.0 - Production on Tue Mar 23 20:41:22 2010
Copyright (c) 1982, 2008, Oracle. All rights reserved.
Connected to an idle instance.
SQL> startup
ORACLE instance started.
Total System Global Area 8417955840 bytes
Fixed Size 2161312 bytes
Variable Size 4429186400 bytes
Database Buffers 3959422976 bytes
Redo Buffers 27185152 bytes
Database mounted.
Database opened.
SQL> exit
启动成功
