最近在学习informix数据库的知识，虽然感觉是个不怎么样的数据库，但既然工作有需要就还是要学习一下的。之前周末在家装了虚拟机装了informix，今天进行初始化的时候却不成功了。报错Fatal error in shared memory initialization。看了一下online.log提示
DISK INITIALIZATION ABORTED: potential instance overwrite detected. To disable this check, set FULL_DISK_INIT to 1 in your config file and retry.
03:34:52 oninit: Fatal error in shared memory initialization
03:32:52 IBM Informix Dynamic Server Stopped.
03:34:52 mt_shm_remove: WARNING: may not have removed all/correct segments
最后还是在IBM informatio center找到答案。
Cause
When the operating system tried to remove the shared-memory segments associated with the database server, the last segment did not equal the last segment registered internally. This situation is probably due to the unexpected failure of the database server.
Action
Remove any segments that were not cleaned up.
按其操作，在onconfig文件中找到FULL_DISK_INIT，将其后的0改为1，再将启动，成功！
想想，之所以出现同样的问题，最有可能是我没有正常关闭Informix就启动操作系统了。