* Stan Hoeppner <s...@hardwarefreak.com>: > Does this machine have more than 4GB of RAM? You do realize that merely > utilizing PAE will cause an increase in context switching, whether on > bare medal or in a VM guest. It will probably actually be much higher > with a VM guest running a PAE kernel. Also, please tell me the ESX > kernel you're running is native 64 bit, not 32 bit. If the VMWare > kernel itself is doing PAE, as well as the guest Linux kernel, this may > fully explain the performance disaster you have on your hands, if it is > indeed due to context switching.
It sure work with 1.2.x now, so that's not really the problem > The bigger question is, why does this problem surface so readily while > running Dovecot 2.0.x and not while running Dovecot 1.2.x? EXACTLY > Is 1.2.x merely tickling the dragon's chin, whereas 2.0.x is sticking > it's head into the dragon's mouth? I'd say the difference between 1.2 and 2.0 is so dramatic that it's probably something else. > This very well may be the case. You need to also look at the CONFIG_HZ= > value of the Linux kernel of the guest. If it's a tickless kernel you > should be fine. If tickless, IIRC, you should see CONFIG_NO_HZ=y. # fgrep HZ config-2.6.32-23-generic-pae CONFIG_NO_HZ=y # CONFIG_HZ_100 is not set CONFIG_HZ_250=y # CONFIG_HZ_300 is not set # CONFIG_HZ_1000 is not set CONFIG_HZ=250 CONFIG_MACHZ_WDT=m -- Ralf Hildebrandt Geschäftsbereich IT | Abteilung Netzwerk Charité - Universitätsmedizin Berlin Campus Benjamin Franklin Hindenburgdamm 30 | D-12203 Berlin Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962 ralf.hildebra...@charite.de | http://www.charite.de
