From owner-freebsd-fs@freebsd.org Sun Mar 27 23:40:20 2016 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 19721AE007A for ; Sun, 27 Mar 2016 23:40:20 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2001:1900:2254:206a::16:76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id E446D1658 for ; Sun, 27 Mar 2016 23:40:19 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from bugs.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id u2RNeJFb050893 for ; Sun, 27 Mar 2016 23:40:19 GMT (envelope-from bugzilla-noreply@freebsd.org) From: bugzilla-noreply@freebsd.org To: freebsd-fs@FreeBSD.org Subject: [Bug 199189] SWAP on ZFS can crash server Date: Sun, 27 Mar 2016 23:40:19 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: 10.1-STABLE X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Many People X-Bugzilla-Who: cmangin@arobas.net X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: freebsd-fs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 27 Mar 2016 23:40:20 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D199189 Chris M changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |cmangin@arobas.net --- Comment #17 from Chris M --- 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.=