建立表空间时出现 shared memory not initialized for INFORMIXSERVER

如题出现错误，建立表空间失败，具体情况如下：
输入：onspaces -c -d plogdbs -p /opt/informix/chunks/plogchk -o 0 -s 2000000
输出：shared memory not initialized for INFORMIXSERVER 'testserver'

查看onstat -m：
IBM Informix Dynamic Server Version 11.50.FC9DE -- On-Line -- Up 01:19:12 -- 149196 Kbytes

Message Log File: /opt/informix/tmp/online.log
20:14:43  Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns blocked 0, Plog used 2, Llog used 2

20:29:44  Checkpoint Completed:  duration was 0 seconds.
20:29:44  Thu Nov  6 - loguniq 1, logpos 0x6018, timestamp: 0xe1 Interval: 5

20:29:44  Maximum server connections 0
20:29:44  Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns blocked 0, Plog used 2, Llog used 2

20:44:44  Checkpoint Completed:  duration was 0 seconds.
20:44:44  Thu Nov  6 - loguniq 1, logpos 0x8018, timestamp: 0xeb Interval: 6

20:44:44  Maximum server connections 0
20:44:44  Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns blocked 0, Plog used 2, Llog used 2

20:59:45  Checkpoint Completed:  duration was 0 seconds.
20:59:45  Thu Nov  6 - loguniq 1, logpos 0xa018, timestamp: 0xf5 Interval: 7

20:59:45  Maximum server connections 0
20:59:45  Checkpoint Statistics - Avg. Txn Block Time 0.000, # Txns blocked 0, Plog used 2, Llog used 2

查看ipcs：
------ Shared Memory Segments --------
key        shmid      owner      perms      bytes      nattch     status      
0x52564801 655364     informix   660        119336960  9                       
0x52564802 688133     informix   660        33439744   9                       

------ Semaphore Arrays --------
key        semid      owner      perms      nsems     
0x00000000 163844     root       660        9         
0x00000000 196613     root       660        9         
0x00000000 327686     informix   660        9         

------ Message Queues --------
key        msqid      owner      perms      used-bytes   messages   

小弟初学，感谢各位大神的帮助！！

补充一下，初步认为是Maximum server connections 数量的问题...不明白为什么是0，能不能改？