On Thu, Aug 16, 2012 at 6:44 PM, Garrett Cooper <yaneg...@gmail.com> wrote: > On Thu, Aug 16, 2012 at 5:46 PM, Gezeala M. Bacuño II <geze...@gmail.com> > wrote: >> Hello fellow listers, >> >> On a server with 512GB RAM it appears that vm.kmem_size_max is not >> being auto-tuned to use >329853485875 (~307GB). >> >> On this machine vm.kmem_size is equal to vm.kmem_size_max >> >> # from sysctl >> vm.kmem_size_max: 329853485875 >> vm.kmem_size: 329853485875 >> >> On a machine with 1GB of RAM, I have successfully set vm.kmem_size_max >> to 330GB and vm.kmem_size automatically adjusts to 1GB even if I >> manually set it in /boot/loader.conf. >> >> But on the machine with 512GB of RAM it just resets. For the machine >> to boot, we need to go to the loader prompt and issue: >> >> OK set vm.kmem_size_max="300G" >> OK boot >> >> On all PCBSD (8,9) or FreeBSD (8.1,8.2,9) machines we have, >> vm.kmem_size_max is always set to 329853485875. >> >> How can I increase vm.kmem_size_max to use at least 500GB? And how is >> 329853485875 determined (formula)? I need to increase vm.kmem_size_max >> and vm.kmem_size so I can set vfs.zfs.arc_max (ZFS ARC) to use say >> 490GB. >> >> I'm browsing thru the source code at >> http://fxr.watson.org/fxr/search?v=FREEBSD9&string=vm.kmem_size_max >> and I'm still trying to make sense of how vm.kmem_size_max is >> computed. >> >> I have posted the same topic on forums.freebsd.org but I'm not getting >> any recommendations. >> >> Please see the link for additional details: >> http://forums.freebsd.org/showthread.php?t=33977 > > Have you tried defining VM_KMEM_SIZE_MAX to your target value? > > Its architecture specific BTW... see > sys/<architecture>/include/vmparam.h -- look for `VM_KMEM_SIZE_MAX`.
Also, it's a tunable, not a sysctl... so you need to set the value in /boot/loader.conf . -Garrett _______________________________________________ freebsd-performance@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-performance To unsubscribe, send any mail to "freebsd-performance-unsubscr...@freebsd.org"
