Date: Sun, 27 Mar 2016 23:40:19 +0000 From: bugzilla-noreply@freebsd.org To: freebsd-fs@FreeBSD.org Subject: [Bug 199189] SWAP on ZFS can crash server Message-ID: <bug-199189-3630-tPj7kzp1O2@https.bugs.freebsd.org/bugzilla/> In-Reply-To: <bug-199189-3630@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=199189 Chris M <cmangin@arobas.net> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |cmangin@arobas.net --- Comment #17 from Chris M <cmangin@arobas.net> --- I'd like to point out this page which has relevant information for those wishing to tune the VM system: https://wiki.freebsd.org/AvgPageoutAlgorithm The tunable vm.pageout_wakeup_thresh hasn't been mentioned here yet and seems to be important for the way the the VM subsystem works. So with that in mind, here's my current configuration for a 8Gb machine with swap on zvol. vm.v_free_severe=20460 vm.v_free_min=32768 vm.v_free_target=51200 vm.pageout_wakeup_thresh=36044 vfs.zfs.arc_free_target=36044 Note that I've picked: vm.pageout_wakeup_thresh = vm.v_free_min * 11/10 vfs.zfs.arc_free_target = vm.pageout_wakeup_thresh as these are the way they are calculated by default. As a reference, the defaults values for my system are: vm.v_free_reserved=2650 (untouched) vm.v_free_severe=7642 vm.v_free_min=12634 vm.v_free_target=42586 vm.pageout_wakeup_thresh=13893 vfs.zfs.arc_free_target=13893 I submitted my system to memory pressure, notably by runs of poudriere generating up to 3Gb of swap usage. I'm happy to report that my system remained rock stable and very responsive during the tests. -- You are receiving this mail because: You are the assignee for the bug.home | help
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