From owner-freebsd-questions@freebsd.org Fri Jun 8 14:30:10 2018 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 571EF101C1FF for ; Fri, 8 Jun 2018 14:30:10 +0000 (UTC) (envelope-from feenberg@nber.org) Received: from mail2.nber.org (mail2.nber.org [198.71.6.79]) by mx1.freebsd.org (Postfix) with ESMTP id E187B845BA for ; Fri, 8 Jun 2018 14:30:09 +0000 (UTC) (envelope-from feenberg@nber.org) Received: from sas1.nber.org (sas1.nber.org [198.71.6.89]) by mail2.nber.org (8.15.2/8.15.2) with ESMTPS id w58E2Wua056365 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 8 Jun 2018 10:02:32 -0400 (EDT) (envelope-from feenberg@nber.org) Date: Fri, 8 Jun 2018 10:02:31 -0400 (EDT) From: Daniel Feenberg To: Christos Chatzaras cc: FreeBSD Subject: Re: Toshiba disk low performance In-Reply-To: <18DD35BD-0DA5-4186-9633-F9270744F9AD@cretaforce.gr> Message-ID: References: <20180607171933.6b4babd094f4d056da797cf5@sohara.org> <5D96200B-649B-4851-9FC6-F56F3188326B@cretaforce.gr> <18DD35BD-0DA5-4186-9633-F9270744F9AD@cretaforce.gr> User-Agent: Alpine 2.21 (LRH 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-KLMS-Rule-ID: 1 X-KLMS-Message-Action: clean X-KLMS-AntiSpam-Status: not scanned, disabled by settings X-KLMS-AntiSpam-Interceptor-Info: not scanned X-KLMS-AntiPhishing: Clean, 2018/06/06 14:48:24 X-KLMS-AntiVirus: Kaspersky Security 8.0 for Linux Mail Server, version 8.0.1.721, bases: 2018/06/08 09:31:00 #8604819 X-KLMS-AntiVirus-Status: Clean, skipped X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Jun 2018 14:30:10 -0000 On Fri, 8 Jun 2018, Christos Chatzaras wrote: > I did some benchmarks and the problem exist in both Linux and FreeBSD. > > I benchmark a server with Toshiba disks and a server with Seagate disks. > > First I install debian without RAID-1. Then I install iozone. > > Tests done with hdparm to test disk bandwidth and iozone to test random read/writes. > > Here are the results: > > https://hastebin.com/gayidosaju.pas > > As you can see the bandwidth for the Toshiba disks is slower than Seagate but this doesn't really matter. > > The problem is the second test that does random read/writes which show the Toshiba has 10 times slower random write speed than the Seagate. > > That's why the issue happens mostly during a "mysql import" and not > other server tasks. Assuming that Smartdisk doesn't show a problem, don't you think that for some good or bad reason, the writes to the Seagate are async and writes to the Toshiba are sync? Perhaps FreeBSD has some rules about the default that Toshiba triggers in a different way than Seagate? Daniel Feenberg