Turbo Boost will not hurt performance. Unless you have 100% load on all cores it will actually improve performance (vastly, in terms of bursty workloads). The issue you have could be related to CPU cores going to sleep mode. Put "intel_idle.max_cstate=3? on the kernel command line (I ran with =2 but I think that disables Turbo Boost) and see what happens. You can find the CPU states counter in /sys. BIOS is usually worthless because while it says ?max performance? the OS is still free to take control to some extent and kernel usually does the right thing with the right settings if it sees it all, while BIOS couldn?t care less what happens in your OS? Jan > On 26 May 2015, at 06:54, Tuomas Juntunen <tuomas.juntunen at databasement.fi> wrote: > > Hi > > I wanted to share my findings of running ceph on HP servers. > > We had a lot of problems with CPU load, which was sometimes even 800. We were trying to figure out why this happens even while not doing anything special. > > Our OSD nodes are running DL380 G6 with Dual Quad core cpu?s and 32gb memory. > > The solution we found to work was to set the following settings in bios > > HP Power Profile Mode: Maximum Performance > Power Regulator Mode: Static High Performance > Intel? Turbo Boost Technology: Disabled > > With these settings our loads never go over 20 and there are no ?hangs? in writes or reads at any time. > > If anyone else has any experiences with these settings, I would appreciate to hear about your findings. The Turbo Boost, is, I would assume the biggest thing here. When CPU frequency is adjusted, the CPU?s ?hang? for a while to do the adjustment, and when the adjustment happens a lot, it creates this high load. > > Br, > Tuomas > _______________________________________________ > ceph-users mailing list > ceph-users at lists.ceph.com <mailto:ceph-users at lists.ceph.com> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com <http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com> -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20150526/e7ed4732/attachment.htm>
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