From owner-freebsd-stable@FreeBSD.ORG Thu Apr 28 17:34:23 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id BADA4106566B for ; Thu, 28 Apr 2011 17:34:23 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id 4F2DD8FC12 for ; Thu, 28 Apr 2011 17:34:22 +0000 (UTC) Received: by fxm11 with SMTP id 11so2837583fxm.13 for ; Thu, 28 Apr 2011 10:34:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=lwvZzPSt6RPZkxIYpuD8jDXGLQzrrGNGJ3VymA+2fT8=; b=gkkrXXp6ocupfcZgLlsmkVtMpp6pXQXWbX/Z88yZHY6aXTkZ4UAOxd4gX+vJt/I1DX pSEg0KwA+kdFzLgkDFcHyEi9X5WJtkL5Y2shijqp3jWt89XYDDyrA3q/KUonEu/qmNNj DAR719hl1AKR9mp/kVl/ixi8f17o1XLpe9Ikc= 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=RwitEre7IrCt/+qtXuGa6IalFG9I0iofa3/PIyW1OtUuC91XoXjnMjaeOe4mzBSFl3 Yacx8Fb0xSoFh/7y7AFLcQ22fcYNXRuZA9hzeICTev8fGo7ATLZmAyNRtLDYPAgP70+T FKWP17JaDi64Kf7ayk+DLrDZcD8KZf1wglegE= MIME-Version: 1.0 Received: by 10.223.97.142 with SMTP id l14mr885821fan.111.1304012061922; Thu, 28 Apr 2011 10:34:21 -0700 (PDT) Received: by 10.223.20.145 with HTTP; Thu, 28 Apr 2011 10:34:21 -0700 (PDT) In-Reply-To: <4DB9887A.4080109@ronner.org> References: <537A8F4F-A302-40F9-92DF-403388D99B4B@gsoft.com.au> <4DB9887A.4080109@ronner.org> Date: Thu, 28 Apr 2011 12:34:21 -0500 Message-ID: From: Adam Vande More To: Thomas Ronner Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-stable@freebsd.org Subject: Re: ZFS vs OSX Time Machine X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 28 Apr 2011 17:34:23 -0000 On Thu, Apr 28, 2011 at 10:32 AM, Thomas Ronner wrote: > On 4/28/11 4:03 PM, Daniel O'Connor wrote: > >> Does anyone else use ZFS to store TM backups? >> >> I find that whenever my laptop (over wifi!) starts a TM the ZFS machine >> it's backing up to grinds to a halt.. Other systems streaming stuff over NFS >> from it also tend to stall.. >> > > > Are you using zfs compression? If so, try turning that off. > > I have a pool with a couple of filesystems with gzip-9 compression enabled. > Whenever I write (using zfs receive, it is a backup server) to one of those > volumes the whole pool stalls with lots of disk activity. Even creating a > snapshot on another filesystem within the same pool lasts a couple of > minutes. > > Does anyone know how to make this perform a little better? It's only > writing small amounts (70-100 ops/s, 1 MB/s) on an otherwise idle pool. > Still the drive leds blink like crazy. One of my two CPU cores is maxed out, > the other is idle. I suppose it won't get any faster (it's CPU bound because > of the heavy gzip compression), but why is the pool so slow? Is zfs receive > using synchonous writes? > gzip-9 is very poor choice for most datasets. It's going to be extremely slow especially with data that can't be compressed easily eg data that already compressed or encrypted. So yeah, if you're running into a cpu bottleneck, change your compression algo. I find lzjb to be a good one for general use. And to the OP, I'm not familar with TM, but see if disabling sendfile in any of your daemons helps. Also I don't think you want this setting: vfs.zfs.cache_flush_disable=1 -- Adam Vande More