Starting the new version of Informix
After installing the new database server, start the server. Do not perform disk-space initialization, which overwrites whatever is on the disk space.
Prerequisite: If you installed Informix® as user root, you must switch to user informix before starting the server.
Start the new version of Informix for the first time by running oninit command on UNIX or by using the Service control application on Windows.
As Informix starts for the first time, it modifies certain disk structures. This operation should extend the initialization process by only a minute or two. If your disks cannot accommodate the growth in disk structures, you will find a message in the message-log file that instructs you to run an oncheck command on a table. The oncheck utility will tell you that you need to rebuild an index. You must rebuild the index as instructed.