shm.create(): error creating shm 2 No such file or directory

最近看到ITPUB上有这样一个帖子，觉得有点意思，收录一下，以为借鉴。

这位朋友的Apache和Oracle运行在同一台主机上：

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

为了解决这个问题，这位同学的解决方法是：
因此，我写了一个脚本，来定时检测并清理。一直很有效。

当Apache和Oracle跑在同一台主机上时，这个脚本就出现了Bug：

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。由于脚本中缺少必要的判断，Oracle的共享内存段也别清除，所以Oracle数据库也挂了，alterlog文集中记录了如下信息：

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:

Oracle数据库是需要再系统上分配共享内存段的，这个是基本的常识，在故障之后，这位同学才想起来：

[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