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/> References: <bug-199189-3630@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D199189 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:=20 https://wiki.freebsd.org/AvgPageoutAlgorithm The tunable vm.pageout_wakeup_thresh hasn't been mentioned here yet and see= ms 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=3D20460 vm.v_free_min=3D32768 vm.v_free_target=3D51200 vm.pageout_wakeup_thresh=3D36044 vfs.zfs.arc_free_target=3D36044 Note that I've picked: vm.pageout_wakeup_thresh =3D vm.v_free_min * 11/10 vfs.zfs.arc_free_target =3D 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=3D2650 (untouched) vm.v_free_severe=3D7642 vm.v_free_min=3D12634 vm.v_free_target=3D42586 vm.pageout_wakeup_thresh=3D13893 vfs.zfs.arc_free_target=3D13893 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 rema= ined rock stable and very responsive during the tests. --=20 You are receiving this mail because: You are the assignee for the bug.=
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