From owner-freebsd-bugs@freebsd.org Mon Jun 18 07:44:28 2018 Return-Path: Delivered-To: freebsd-bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 08647101AC3A for ; Mon, 18 Jun 2018 07:44:28 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mailman.ysv.freebsd.org (mailman.ysv.freebsd.org [IPv6:2001:1900:2254:206a::50:5]) by mx1.freebsd.org (Postfix) with ESMTP id 7B1C672FA1 for ; Mon, 18 Jun 2018 07:44:27 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: by mailman.ysv.freebsd.org (Postfix) id 35777101AC39; Mon, 18 Jun 2018 07:44:27 +0000 (UTC) Delivered-To: bugs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 23BFF101AC38 for ; Mon, 18 Jun 2018 07:44:27 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.ysv.freebsd.org (mxrelay.ysv.freebsd.org [IPv6:2001:1900:2254:206a::19:3]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mxrelay.ysv.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id B722172F9D for ; Mon, 18 Jun 2018 07:44:26 +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 mxrelay.ysv.freebsd.org (Postfix) with ESMTPS id 207A21EFC7 for ; Mon, 18 Jun 2018 07:44:26 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.118]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id w5I7iPQq007122 for ; Mon, 18 Jun 2018 07:44:25 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id w5I7iPfi007121 for bugs@FreeBSD.org; Mon, 18 Jun 2018 07:44:25 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 163461] [vfs] vfs.zfs.arc_max/vfs.zfs.arc_meta_limit defaults aren't wise Date: Mon, 18 Jun 2018 07:44:26 +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: unspecified X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Only Me X-Bugzilla-Who: FreeBSD@ShaneWare.Biz X-Bugzilla-Status: Open X-Bugzilla-Resolution: X-Bugzilla-Priority: Normal X-Bugzilla-Assigned-To: bugs@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-bugs@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 18 Jun 2018 07:44:28 -0000 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D163461 Shane changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |FreeBSD@ShaneWare.Biz --- Comment #3 from Shane --- Rather than start a new report I will jump into this old one. Currently arc_max is set to the larger of (5/8 of kmem_size) or (kmem_size minus 1G) - for a system with 8G of ram 5/8 is 5G with kmem size minus 1G a= bout 6GB While that sounds ok, we also have max_wired which seems to default to 5G (I see that on an 8G and 16G setup) the issue results from arc being wired but= not included in the max_wired count, that means an 8G system allows 10G to get wired! a 16GB system allows 20GB to be wired! When a system has more than 70% of physical ram wired, it gets exteremely s= low and over 80% wired gives a very high chance of needing a hard reset. At the minimum we need to consider max_wired in the arc_max calculation. I do believe the arc_max default should be even smaller to be better suited= to more common setups that run processes that use ram, a sysadmin starting a f= ile server that wants to use most of the ram for cache should know how to set t= his as desired, the other 80-90% of users shouldn't have to adjust a setting th= at is suited to the smaller use case. --=20 You are receiving this mail because: You are the assignee for the bug.=