我的平台是redhat as 3 ，oracle 9204.
其他应用是apache，resin等。
因为以前发现apache运行时间长以后会出现共享内存不足的错误，具体错误信息如下：
[Fri Apr 13 06:00:03 2007] [error] shm.create(): error creating shm 2 No such file or directory
[Fri Apr 13 06:00:03 2007] [error] shm.create(): error creating shm /home/apache/logs/shm.file
[Fri Apr 13 06:00:03 2007] [warn] pid file /home/apache/logs/httpd.pid overwritten -- Unclean shutdown of previous Apache run?
[Fri Apr 13 06:00:03 2007] [emerg] (28)No space left on device: Couldn't create accept lock
因此，我写了一个脚本，来定时检测并清理。一直很有效。
前一段时间，新开了一个小应用，也是apache的应用，由于没地方放了，就放到oracle机器上了，一直运行比较好；
今天早上接到信息，说新开的这个apache应用服务停止了，打开log一看，又是共享内存的问题，二话不说，把原来的脚本在系统上跑了一遍，restart apache，ok。系统可以了。
过了几分钟。问题大了，说oracle服务宕了。赶紧检查，ps -ef|oracle 服务都没了，看alterlog发现如下信息：
Errors in file /opt/oracle/admin/sc1/bdump/sc1_reco_5195.trc:
ORA-27157: OS post/wait facility removed
ORA-27300: OS system dependent operation:semop failed with status: 43
ORA-27301: OS failure message: Identifier removed
ORA-27302: failure occurred at: sskgpwwait1
Fri Apr 13 10:10:46 2007
Errors in file /opt/oracle/admin/sc1/bdump/sc1_smon_5193.trc:
ORA-27157: OS post/wait facility removed
ORA-27300: OS system dependent operation:semop failed with status: 43
ORA-27301: OS failure message: Identifier removed
ORA-27302: failure occurred at: sskgpwwait1
Fri Apr 13 10:10:46 2007
RECO: terminating instance due to error 27157
Fri Apr 13 10:10:46 2007
Errors in file /opt/oracle/admin/sc1/udump/sc1_ora_23824.trc:
ORA-27153: wait operation failed
ORA-27300: OS system dependent operation:semop failed with status: 22
ORA-27301: OS failure message: Invalid argument
ORA-27302: failure occurred at: sskgpwwait2
Fri Apr 13 10:10:46 2007
Errors in file /opt/oracle/admin/sc1/bdump/sc1_lgwr_5189.trc:
知道是系统问题导致oracle宕机了。想到刚才的操作，怀疑把oracle的共享内存也给误清理了，好在db能正常启动，把数据库启动后，检查共享内存：
[root@oracle]# ipcs -s
------ Semaphore Arrays --------
key semid owner perms nsems
0x00000000 4849664 nobody 600 1
0x00000000 4882433 nobody 600 1
0x00000000 4915202 nobody 600 1
0x00000000 4947971 nobody 600 1
0x00000000 4980740 nobody 600 1
0xbeae576c 5111813 oracle 640 201
0xbeae576d 5144582 oracle 640 201
0xbeae576e 5177351 oracle 640 201
0xbeae576f 5210120 oracle 640 201
0xbeae5770 5242889 oracle 640 201
0x00000000 5275658 nobody 600 1
0x00000000 5308427 nobody 600 1
0x00000000 5341196 nobody 600 1
0x00000000 5373965 nobody 600 1
0x00000000 5406734 nobody 600 1
0x00000000 5439503 nobody 600 1
0x00000000 5472272 nobody 600 1
0x00000000 5505041 nobody 600 1
果然有oracle的共享内存，而我的脚本没有判断。如果只是删除apache用户的共享内存，可以这样
ipcs -s | grep apache | perl -e 'while (<STDIN>
{ @a=split(/\s+/); print `ipcrm sem $a[1]`}'
如果大家谁的应用和我这个类似，一定注意。
