From owner-freebsd-stable@freebsd.org Tue Feb 9 16:14:12 2016 Return-Path: Delivered-To: freebsd-stable@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 70825AA3CB8 for ; Tue, 9 Feb 2016 16:14:12 +0000 (UTC) (envelope-from hausen@punkt.de) Received: from kagate.punkt.de (kagate.punkt.de [217.29.33.131]) (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 143089DF for ; Tue, 9 Feb 2016 16:14:11 +0000 (UTC) (envelope-from hausen@punkt.de) Received: from hugo10.ka.punkt.de (hugo10.ka.punkt.de [217.29.44.10]) by gate2.intern.punkt.de with ESMTP id u19FsYGm068849 for ; Tue, 9 Feb 2016 16:54:34 +0100 (CET) Received: from [217.29.44.208] ([217.29.44.208]) by hugo10.ka.punkt.de (8.14.2/8.14.2) with ESMTP id u19FsYlT071824 for ; Tue, 9 Feb 2016 16:54:34 +0100 (CET) (envelope-from hausen@punkt.de) From: "Patrick M. Hausen" Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Subject: Best practices for ZFS setup for a strictly SSD based system? Message-Id: <2D296837-3B06-4E72-B8B0-A33AE6CE48AE@punkt.de> Date: Tue, 9 Feb 2016 16:54:36 +0100 To: freebsd-stable Mime-Version: 1.0 (Mac OS X Mail 9.2 \(3112\)) X-Mailer: Apple Mail (2.3112) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 09 Feb 2016 16:14:12 -0000 Hi, all, while there is quite a bit of documentation on how to improve ZFS = performance by using a combination of rotating disks and SSDs, I have not found much = about an SSD only setup. We are planning to try a hosting server with 8 SATA SSDs with ZFS. = Things I am not at all sure about: * Does the recommended limit of 6 disks for a RAIDZ2 still hold? 2x 4 disks is quite a bit of overhead, could I use all 8 in one vdev and get away with it? (The maximum of 6 recommendation is in some old Sun doc) * Will e.g. MySQL still profit from residing on a mirror instead of a RAIDZ2, even if all disks are SSDs? * Does a separate ZIL and/or ARC cache device still make sense? Any pointers or direct help greatly appreciated. Or should I take this = to freebsd-fs@? Thanks and best regards, Patrick --=20 punkt.de GmbH * Kaiserallee 13a * 76133 Karlsruhe Tel. 0721 9109 0 * Fax 0721 9109 100 info@punkt.de http://www.punkt.de Gf: J=C3=BCrgen Egeling AG Mannheim 108285