From owner-freebsd-questions@FreeBSD.ORG Wed Dec 22 21:17:52 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5F829106564A for ; Wed, 22 Dec 2010 21:17:52 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-fx0-f49.google.com (mail-fx0-f49.google.com [209.85.161.49]) by mx1.freebsd.org (Postfix) with ESMTP id E495B8FC18 for ; Wed, 22 Dec 2010 21:17:51 +0000 (UTC) Received: by fxm19 with SMTP id 19so5397303fxm.36 for ; Wed, 22 Dec 2010 13:17:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type; bh=WCjANHwmbo8lzS7LMiF4SINJ9q/ZCubemY91k+PlBc4=; b=jkobScNjP0FEn8yQwoikLyGzAKYDUVPrCTr4SCJrzAI0YfQY6z2eRG6vDurFgs0fqu 4jbZxtZ7s0gv4wuV23DggoBQFAqFjJDznMLSsnTDGkOjZ78Z3+EtyAOjfLEcNJP7+8RU Tz+fbAPK326wBKXqedlbWiLDU/c3OsgB0s7aI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=paFbvWkdt0T+DxQ42jpj6sPK1FQuu+dpBuLKtXKzA7qghpzJTz6R0rEgaPOk9HJUmU 9MfjX4zKFoIPDwvidacQBHTTUav6nAcICpm5ybEXabVuo9K589U2GrTiLbKUxyu/cLu2 Rta/Uu92NAcT6aaDObRLE39R/Muk1poz7AHvk= MIME-Version: 1.0 Received: by 10.223.85.203 with SMTP id p11mr46130fal.108.1293052669123; Wed, 22 Dec 2010 13:17:49 -0800 (PST) Received: by 10.223.114.4 with HTTP; Wed, 22 Dec 2010 13:17:49 -0800 (PST) In-Reply-To: References: Date: Wed, 22 Dec 2010 15:17:49 -0600 Message-ID: From: Adam Vande More To: Omer Faruk SEN Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: FreeBSD Subject: Re: 9 TB single device and zfs X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Dec 2010 21:17:52 -0000 On Wed, Dec 22, 2010 at 2:38 PM, Omer Faruk SEN wrote: > Is it suggested to create a zfs on a single 9 TB volume? Depends on your need. You really haven't provided enough info to give advice ie how many disks do you have, what storage capacity do you need, performance etc. ZFS capability are better utilized when ZFS, and not the storage controller is providing the raid/mirroring functionality, but this has some drawbacks as well. > There is > hardware raid and I am thinking to enable write-back cache on that hw > based raid card. > Raid-z/mirror stripes have some advantages over hw raid so you may wish to grow your understanding of the differences before proceeding. You should also ensure your hardware correctly handles cache flush requests as a few disks and some SSD's don't. If the hardware makes false reports to ZFS, you can experience different forms of pool corruption in a loss of power situation. You'll almost certainly want a BBU if you're going to go this route. http://www.solarisinternals.com/wiki/index.php/ZFS_Evil_Tuning_Guide -- Adam Vande More