I thought it will be a good idea to make a post as it will help in case someone else faces these issues. I trust this gives an idea how each entry in Notes.ini can mean a lot for the Domino Server to be functioning properly. This article discusses two tips.
"Server exiting: Could not open ID file".
I got an interesting issue with one of the domino servers. The server had crashed with the error on domino console screen "Server exiting: Could not open ID file". Interestingly there is no much help available in the Lotus Knowledge base, IBM Support docs and even the most preferred google search.
Finally I thought to do some research on it. I initially thought that the ID file may have become corrupted. I replaced the ID file from the Backup repository and tried to make the server up but resulted with same error. Then I copied the ID file to my local and verified to make sure the ID file is in right shape. Next I replaced the NAB from copying a fresh NAB from one of the adjacent domino servers, but even this was of (very) less help.
So I thought to look through the Notes.Ini which keeps all the domino configuration and Notes Server uses this file to bring all the specified services up and running. When I was looking at all the entries one by one in the Notes.ini, I found that the entry ServerKeyFilename=Server17.id was missing. I made that entry which fixed the issue.
I checked back with the team and someone who was very new to the team confirmed that he accidentally removed that entry. There is another tip - make sure you have the proper controls in place to prevent accidents.
Also most of the time we run weekend maintenance to all the database on the domino servers and sometimes we see the server goes into unresponsive mode when the maintenance is running on the names.nsf or log.nsf
So there might be situations where you want to exclude maintenance to run on specific database. You can do so by putting an entry in Notes.ini