Some days ago I had some problems with Enterprise Manager. After a problem with space on disk, one of the instances of the EM refused to start after cleaned the logs that was filling the system disk.
As other instances came back to work normally, I thought that the problem was in the configuration and I reset it using EMCA. It didn’t work. I tried to solve every error that appeared in logs and anything worked. Every time I tried to start it, it took about 10 minutes to show me the failed status.
Finally, I have reached an uncommon error saying that a configuration file was given a wrong parameter. I revised it a lot of times and didn’t find the wrong parameter. As a last try, I changed some parameters to force an error and possibly get some advice from the logs. For my surprise, the user oracle couldn’t save the file. I was using vim at this time. So I change the ownership of the file to oracle and voilá, EM started. So, it’s a reminder to review my permissions.