From owner-freebsd-fs@FreeBSD.ORG Sat Sep 17 04:13:42 2011 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BE0EC106567A for ; Sat, 17 Sep 2011 04:13:42 +0000 (UTC) (envelope-from boydjd@jbip.net) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id 4FAED8FC08 for ; Sat, 17 Sep 2011 04:13:42 +0000 (UTC) Received: by fxg9 with SMTP id 9so3122152fxg.13 for ; Fri, 16 Sep 2011 21:13:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jbip.net; s=google; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type; bh=qe+Tue998WPZ2PSWGCtNmCVu962f027KKYFMzksLo9M=; b=FN/vPQLxJOQ6OBFjd6DkrNfIn0yULCM+29xpemOcO9pjkI+Pwnm7y2+KqEFAu4afNu 5zP9sdpHW45dlOF0WJmgyHakg8YEvqrBtbFK/Z79zPy093gHKBHpdBSrBckrlswegVdA 42fpSuZ68TZ1438aRFUz4C90e58Jafy8dNnjE= Received: by 10.223.49.140 with SMTP id v12mr354664faf.67.1316231352234; Fri, 16 Sep 2011 20:49:12 -0700 (PDT) MIME-Version: 1.0 Received: by 10.223.58.133 with HTTP; Fri, 16 Sep 2011 20:48:52 -0700 (PDT) In-Reply-To: <1316222526.31565.YahooMailNeo@web121205.mail.ne1.yahoo.com> References: <1316222526.31565.YahooMailNeo@web121205.mail.ne1.yahoo.com> From: Joshua Boyd Date: Fri, 16 Sep 2011 23:48:52 -0400 Message-ID: To: Jason Usher Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: "freebsd-fs@freebsd.org" Subject: Re: ZFS obn FreeBSD hardware model for 48 or 96 sata3 paths... X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Sep 2011 04:13:42 -0000 On Fri, Sep 16, 2011 at 9:22 PM, Jason Usher wrote: > > So I will boot of a pair of mirrored SSDs formatted UFS2 - easy. But I > would also like to spec and use a ZIL+L2ARC and am not sure where to go ... > the system will be VERY write-biased and use a LOT of inodes - so lots of > scanning of large dirs with lots of inodes and writing data. Something like > 400 million inodes on a filesystem with an average file size of 150 KB. > 400 million inodes on a single file system is not going to work out well. It doesn't matter /what/ file system you use, it will end up barfing. I'd recommend creating lots of zfs filesystems on your zpools. With 400 million inodes, I'm HOPING that they're atleast divided into subdirectories, create a zfs for each subdirectory. That'll help a lot. > > - can I just skip the l2arc and just add more RAM ? Wouldn't the RAM > always be faster/better ? Or do folks build such large L2arcs (4x200 GB SSD > ?) that it outweighs an extra 32 GB of RAM ? > More RAM is always faster, but striped SSDs are pretty fast too. I'd max out the RAM on this sort of server, and then add L2ARC devices if needed. > > - provided I maintain the free pcie slot(s) and/or free 2.5" drive slots, > can I always just add a ZIL after the fact ? I'd prefer to skip it for now > and save that complexity for later... > Yes, you can add a ZIL later. > > Thanks very much for any comments/suggestions. > > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" > -- Joshua Boyd E-mail: boydjd@jbip.net http://www.jbip.net