Stan Hoeppner wrote: > Frankly I'd rather not waste the time on it at this point. You > solved my original problem Bob! Thank again. That was the > important takeaway here. Now we're into minutia (which can be fun > but I'm spending way too much time on debian-user email the last few > days) Glad to have been able to help with your original problem! And I agree, I am spending way too much time here too. Need to get other work done. :-) > Ahh, something else I just realized. Feel free to slap me if you like. :) I missed that too. > Given this is a production mx mail and web server, it's very likely that daemons > awoke and ate some CPU without causing a highlight change in top. Since I was > intensely watching the convert processes, I may not have noticed, or simply > ignored them. That's a better explanation for the less than 100% CPU per > convert process than anything else, and far more likely. smtpd, imapd, > lighttpdd, etc are frequently firing and eating little bits of CPU. This is a > personal server so the traffic is small, but nonetheless daemons are firing > regularly. Postfix alone fires 3 or 4 daemons when mail arrives. None of these > eat much CPU time, but they all add up. That makes a lot of sense to me. And also when cpu time divides by 1/N where N is the number of processes then if you have more convert processes running then effectively that task will get more total time than will the other tasks. A little bit more here and a little bit less there on the other tasks running. If you had two converts running and one mail task then the mail task would get 1/3rd and the two converts would get 2/3rds. As opposed to one convert and one mail task with 1/2 and 1/2. > And context switching on a 550 MHz CPU with only 128K L2 cache is > going to be expensive when two compute intensive tasks are running. I commend you on keeping that machine running. My main mail and web server was, until the motherboard died very recently, a 400 MHz P2. I was sad to see it go since it had been such a good performer for so many years. Bob
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