From owner-freebsd-questions@freebsd.org Thu Sep 24 04:47:29 2015 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E1417A07B5E for ; Thu, 24 Sep 2015 04:47:29 +0000 (UTC) (envelope-from war@dim.lv) Received: from mail-wi0-f173.google.com (mail-wi0-f173.google.com [209.85.212.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 826CF1880 for ; Thu, 24 Sep 2015 04:47:28 +0000 (UTC) (envelope-from war@dim.lv) Received: by wicge5 with SMTP id ge5so235026877wic.0 for ; Wed, 23 Sep 2015 21:47:21 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-type :content-transfer-encoding; bh=s0YUVKN7Y0b3LsIjQUMuAvX0Zf974zoc/YZ215s/Ox0=; b=QSEDkGgvMiEBECEihUAdP9k7YEzR59yczy3RnFZJoKtOoxdZA8uTbRo13LpC5ES8uW LRNHp+d+T5esp4T4HFzZhoYa7yznVT2pcSD3VFWuD2pDmJaqqbKU0jN3rlnAUm6bMesW tpC4XSPkbK3zZWMLUX7oQNCbEBnn3wSCtBtROzSag5qDbDUd6IsVpD2IX7DjmnbBDrVm gIQn5KGWCQ0tRZYpaZgUvFNmfEIvQ29GAvV8KcmSeUpwMP/RNzqGJslMbtAM39NTbFzc Iw8CHfhrEPX+8f4Ofe8wWfBsOqs9pmPL54JCoRptzHkQaQ3+JhjCqSHo9E5nFISGYxr7 DVHQ== X-Gm-Message-State: ALoCoQni4Y9z4OhBoDVQjYqW68eoPvPnm0Hwi8r8fwrwu47LBhME2xb5hYBKasQs0ciN5zWza5pF X-Received: by 10.194.248.234 with SMTP id yp10mr44607939wjc.24.1443070041598; Wed, 23 Sep 2015 21:47:21 -0700 (PDT) Received: from [192.168.88.18] (balticom-185-141.balticom.lv. [83.99.185.141]) by smtp.googlemail.com with ESMTPSA id gt4sm3477132wib.21.2015.09.23.21.47.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 Sep 2015 21:47:20 -0700 (PDT) Subject: Re: zfs performance degradation To: Paul Kraus , freebsd-questions@freebsd.org References: <56019211.2050307@dim.lv> <37A37E9D-9D65-4553-BBA2-C5B032163499@kraus-haus.org> From: Dmitrijs Message-ID: <56038054.5060906@dim.lv> Date: Thu, 24 Sep 2015 07:47:16 +0300 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <37A37E9D-9D65-4553-BBA2-C5B032163499@kraus-haus.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 24 Sep 2015 04:47:30 -0000 2015.09.23. 23:08, Paul Kraus пишет: > On Sep 22, 2015, at 13:38, Dmitrijs wrote: > >> I've encountered strange ZFS behavior - serious performance degradation over few days. >> >> Could it happen because of pool being 78% full? So I cannot fill puls full? >> Can anyone please advice how could I fix the situation - or is it normal? > > So the short answer (way too late for that) is that you can, in fact, not use all of the capacity of a zpool unless the data is written once, never modified, and you do not have any snapshots, clones, or the like. > > P.S. I assume you are not using DeDupe ? You do not have anywhere enough RAM for that. > > -- > Paul Kraus > paul@kraus-haus.org > Thank you very much for explanation. Am I getting it right - it will not work faster even if I add +4Gb RAM to be 8Gb in total? I am not using DeDuplication and compression, neither planing using them. I've also put down a lot of research for situation here: http://forums.nas4free.org/viewtopic.php?f=66&t=9595 In short: you are right, everything getting slowly when pool fills up. So if I plan to work with data a lot, get decent performance and still be sure I'm on the safe side with mirror-raid1, should I choose another filesystem? Especially, if i do not really need snapshots, clones, etc. Or is it not possible at all, and I should put something like raid0 for work and tolerate slow backup on raid1 at nights? best regards, Dmitriy