From owner-freebsd-hackers@FreeBSD.ORG Sat Jun 5 13:41:52 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B0B611065675; Sat, 5 Jun 2010 13:41:52 +0000 (UTC) (envelope-from mozolevsky@gmail.com) Received: from mail-vw0-f54.google.com (mail-vw0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id 1DEEB8FC18; Sat, 5 Jun 2010 13:41:51 +0000 (UTC) Received: by vws18 with SMTP id 18so292996vws.13 for ; Sat, 05 Jun 2010 06:41:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:mime-version:sender:received :in-reply-to:references:from:date:x-google-sender-auth:message-id :subject:to:cc:content-type; bh=SpsVcLzNlkM5HruhAmPivxnscu2UgHQMEuLzIFy1LtA=; b=VwRIzrmnm3q/femSJtmgJVspyyb121B+Sq909cYy4lIM9a3srjxUzJEpU4pXlMRFrF XnteLUmLsM1BqCvbGSDobRZAdhPtTPCgynQaNTGH0I+rEP+paAIStQg+qoLeWWm3M3qB opofK2ii3ETeF0zvBXsfDrPbeO+pHX8IqRfdE= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type; b=jeG2+8eBELICIxWUX9kiSsZ+DPe47TCmRexGmmaZiCwI6iTAxAn5O0oxWbP8L68jFm V+8+AmJFd9CznD+CwSZfWbtLqEHDVP0yG77bH0AG8zW+DVLFjCEqT65wR59J3f/F8GR1 ng87dQslAVOB6uJdfwN1xnTMuhJ0MRcyMeQ+I= Received: by 10.229.188.70 with SMTP id cz6mr3200115qcb.161.1275745310598; Sat, 05 Jun 2010 06:41:50 -0700 (PDT) MIME-Version: 1.0 Sender: mozolevsky@gmail.com Received: by 10.229.236.15 with HTTP; Sat, 5 Jun 2010 06:41:29 -0700 (PDT) In-Reply-To: <4C0A3262.8010507@wooh.hu> References: <4C09932B.6040808@wooh.hu> <201006050236.17697.bruce@cran.org.uk> <20100605120405.00007954@unknown> <4C0A3262.8010507@wooh.hu> From: Igor Mozolevsky Date: Sat, 5 Jun 2010 14:41:29 +0100 X-Google-Sender-Auth: B9ULtr5oBQ2QqXcR8_qw2Wi8XY4 Message-ID: To: Adam PAPAI Content-Type: text/plain; charset=UTF-8 Cc: freebsd-hackers@freebsd.org, freebsd-questions@freebsd.org Subject: Re: sysbench / fileio - Linux vs. FreeBSD X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 05 Jun 2010 13:41:52 -0000 >>>> /usr/src : zfs with compression enabled >>>> /usr/src : 386.3MB/s >>> Do I understand it well? It seems that zfs with compression enabled on >>> /usr/src with 8KB block size and 16 threads performs 386.3MB/s which >>> is about 6 times better than debian5? I am thinking about this image >>> http://tech-blog.wooh.hu/~wooh/debian_vs_freebsd_io_16_seqwr.png >> >> Yes - on one run it even hit 500MB/s. I suspect, however, that the >> benchmark isn't accurate because it won't be writing typical data. >> Instead it's probably using a buffer that compresses very well. > > Hm.. My ZFS tests showed me the same results. With compression it's > pretty fast. That's hardly a surprise - you take the source code, compress it into virtual non-existence leaving hardly anything to be written to the disk... Obviously if compression speed >> IO speed and the result of the compression is a significant reduction in size, you have a massive gain in writing that data to the disk. -- Igor