About two weeks ago I noticed that the top command, which is running most of the time on the in-house server just to keep the screen busy, was showing a zombie process. I didn’t care much about it. A few days later, someone pointed that out to me. This person, who has little knowledge about computers, thought it was kind of funny that I had a zombie on my computer. I, on the other hand, didn’t think it was that funny. I thought it was logic that the zombie process I had seen before was still there since the computer had not been restarted, but I decided to look into it. I opened another terminal window, so I could have top running and work at the same time. What was my surprise that all the sudden I saw not one but two zombie processes. So freaked out (not really). If the number of zombie processes starts rising up on your machine, there is something wrong going on.
The reason I didn’t freak out was because I knew that the only thing that hand changed was the fact that I had opened another terminal window. So I closed it, and the number of zombie processes came back down to one. I SSHed into the server from my workstation, run top, and closed the terminal window that was running top on the server. The number of zombie processes went down to zero.
So, that was it. My terminal emulator (terminator) becomes a zombie process when running. I still don’t know why. At first I thought it might be standard behavior for terminal emulators, but when I run the default terminal emulator on ubuntu, it did not increase the number of zombie processes. To be fair, I wasn’t really convinced that it was terminator that was on zombie mode, so I searched how to spot zombie processes. I got with this nice blog post: http://www.debian-administration.org/articles/261
I followed the instruction and found out that in fact, it is terminator that is running as zombie. Now the question is why? If you have any idea of why this happens, feel free to share it in the comments section.