From owner-freebsd-fs@FreeBSD.ORG Tue Jul 8 01:06:46 2014 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 43AD295B for ; Tue, 8 Jul 2014 01:06:46 +0000 (UTC) Received: from mail-la0-x236.google.com (mail-la0-x236.google.com [IPv6:2a00:1450:4010:c03::236]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C26F4253A for ; Tue, 8 Jul 2014 01:06:45 +0000 (UTC) Received: by mail-la0-f54.google.com with SMTP id mc6so3501251lab.27 for ; Mon, 07 Jul 2014 18:06:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=Yhiyq6GKKGu5BPXztfpXua6PFaGTfS1XAoE3HzaN69M=; b=wl4J1Knp6YWPfjiFaqlaG7uCLprRvyaq+QjrwYE6EyxIXjYxU7UElNVzZaNy+o82m8 ktglo5oo3MsJPGFm7kgGypzxet/dEFbvFwhWj3ePN3XGxWUKatLv+UxFX0/VcEeBYjgH 5ZD60xWUJ9yYtlPaY5dzpZSAeDcJE7fZm0rnoauGoV/bOvAMRWTnRCdhARW+VaZvWGmb SrgcNzCIJT6ieQRCGacIKi907cAkPQUTDfPH/4tZnUuHQXPBzJixVNr9p5JX2l0JC0yy A8Ygp9mit44RPqYw+4ql5y8/frM6r5XI2hj47QZcZzeQ3o46758R/3VhKtPyuyn4gpus YbJQ== MIME-Version: 1.0 X-Received: by 10.152.37.194 with SMTP id a2mr25689891lak.29.1404781603561; Mon, 07 Jul 2014 18:06:43 -0700 (PDT) Received: by 10.115.2.3 with HTTP; Mon, 7 Jul 2014 18:06:43 -0700 (PDT) Date: Mon, 7 Jul 2014 18:06:43 -0700 Message-ID: Subject: Using 2 SSD's to create a SLOG From: javocado To: FreeBSD Filesystems Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.18 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Jul 2014 01:06:46 -0000 I am interested in adding an SSD "SLOG" to my ZFS system so as to (dramatically) speed up writes on this system. My question is if ZFS will, itself, internally, mirror two SSDs that are used as a SLOG ? What I mean is, if ZFS is already smart enough to create a zpool mirror (or, on my case, a zpool raidz3) then perhaps ZFS is also smart enough to mirror the SLOG to two individual SSDs ? I am hoping to dumbly plug two SSDs onto motherboard SATA ports and just hand them over, raw, to ZFS. Can someone shed some light on how this might, could or should work?