performance effect of mbox to maildir upgrade

[carlaron]

Does anyone know whether my delaying the move to mbox (for various reasons) would contribute to my high load?

I was assuming that it was mostly all the spam coming in, and my system dealing with it... exim and spamd are ususally high, and turning off exim (and spamd with it) during a high load spike always brings the load right down.

But perhaps it is also an inefficiant mbox that is slowing down exim and making it work harder?

Or perhaps making cppop work harder? Most of the time high load is exim, but once in a while cppop jumps to the top of "top".

If mbox is not contrbituing to the high load, then I will put off the upgrade on that until I deal with the high loads from exim problem, and have time to prepare the 400 or so email users for the switchover...

 

[cPanelDavidG]

Does anyone know whether my delaying the move to mbox (for various reasons) would contribute to my high load?

I was assuming that it was mostly all the spam coming in, and my system dealing with it... exim and spamd are ususally high, and turning off exim (and spamd with it) during a high load spike always brings the load right down.

But perhaps it is also an inefficiant mbox that is slowing down exim and making it work harder?

Or perhaps making cppop work harder? Most of the time high load is exim, but once in a while cppop jumps to the top of "top".

If mbox is not contrbituing to the high load, then I will put off the upgrade on that until I deal with the high loads from exim problem, and have time to prepare the 400 or so email users for the switchover...

I'd recommend migrating to maildir if you are seeing cppop (only used on mbox) eating a lot of CPU. mbox is an inherently inefficient method of storing mail (to access a message in the inbox, you must sort through a single file containing the entire contents of the inbox). I know some sysAdmins have reported noticably (or in rare cases: very noticably) lower loads after migrating to maildir. Perhaps you may be one of those relatively rare cases where converting to maildir will have a significant positive impact on server loads, but that's just speculation on my part.

Once you convert to maildir, Courier and Courier-IMAP will handle POP3 and IMAP functionality rather than cppop.