On Mon, 2011-07-11 at 13:47 -0500, Stan Hoeppner wrote: > On 7/11/2011 11:22 AM, li...@truthisfreedom.org.uk wrote: > > > They're showing as between 20 and 24 for the POP3 servers and 1.4 for > > the IMAP servers. > > FULL STOP. Oh my lordy. Something is ridiculously wrong here. You > have 12 physical cores with only ~600 simultaneous pop connections. > That's only 50 per core. Even if those are the 'lowly' 2.4GHz 5645 > chips each core should be able to handle a couple hundred pop > connections. If you were truly hitting an actual load of 20-24, a > single one of those boxes would be bringing your NetApp to its knees > (assuming GbE) due to the amount of IO that would be taking place with > the CPUs this busy.
Good, so my assumption that something was wrong was correct and as the NetApp isn't on its knees... > > So a kernel update is more than sensible... > > Disable HT regardless of kernel upgrading. See if it helps the load > issue with the current kernel. Then go ahead and upgrade the kernel. > If the CentOS repos don't have anything in the 2.6.3x series grab: > http://www.kernel.org/pub/linux/kernel/v2.6/linux-2.6.39.3.tar.bz2 > > and roll your own. Though I'd guess since you're a CentOS user you > probably don't have any experience rolling kernels. LOL. I'm not a fan of Centos but it's what we've got to play with here - We'll be running Debian (or possibly even Gentoo if I have my way...) on the next load of servers and custom kernels aren't an issue. /me misses stage one gentoo installs... :( > Now, considering you're running a many years old version of Dovecot, > which is no longer officially supported, you really need to upgrade. > Safe bet is to grab the latest 1.2.x RPM you can get. We've built our own RPMS for 1.2 - we're upgrading these servers tomorrow... :) Kind regards, Matt
