ORA-27154 ORA-27300 ORA-27301 ORA-27302故障处理

根据经验对系统的内核参数做了一些调整,结果导致数据库启动失败提示报ORA-27154 ORA-27300 ORA-27301 ORA-27302错误

ORA-27154: post/wait create failed
ORA-27300: OS system dependent operation:semget failed with status: 28
ORA-27301: OS failure message: No space left on device
ORA-27302: failure occurred at: sskgpcreates

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根据官方描述:Database Startup Fails with ORA-27300: OS system dependent operation:semget failed with status: 28 (Doc ID 949468.1),出现该问题原因可能是由于kernel.sem参数配置不合适当时,该库的processes配置为:20000,kernel.sem参数配置为:kernel.sem = 250 32000 100 128,参数说明:

kernel.sem = SEMMSL SEMMNS SEMOPM SEMMNI
SEMMSL - max semaphores per array
SEMMNS - max semaphores system wide
SEMOPM - max ops per semop call
SEMMNI - max number of arrays

理论上每个这样的配置最大值SEMMSL*SEMMNI=32000大于process的20000的设置,可是实际上控制每个信号集的信号数量没有达到250,而是只有156,通过ipcs命令可以看

[oracle@xifenfei ~]$ ipcs

------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status      
0x00000000 32768      oracle     640        33554432   30                      
0x00000000 65537      oracle     640        4261412864 30                      
0xc2d167d0 98306      oracle     640        2097152    30                      
0x00000072 131075     root       444        1          1                       

------ Semaphore Arrays --------
key        semid      owner      perms      nsems   
0x450e15bd 0 	      root       666        1
0x0000cace 32769      root       666        1
0x358b172c 327683     oracle     660        104
0x9053d038 11075588   oracle     660        156
0x9053d039 11108357   oracle     660        156
0x9053d03a 11141126   oracle     660        156
0x9053d03b 11173895   oracle     660        156

从而使得SEMMSL*SEMMNI小于processes值,进而数据库启动报ORA-27154 ORA-27300 ORA-27301 ORA-27302,修改kernel.sem = 250 64000 128 256,数据库启动成功