From owner-freebsd-questions@freebsd.org Fri Jun 8 14:46:12 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 1DCAE101CD9B for ; Fri, 8 Jun 2018 14:46:12 +0000 (UTC) (envelope-from chris@cretaforce.gr) Received: from smtpb4.cretaforce.gr (smtpb4.cretaforce.gr [78.47.134.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "*.cretaforce.gr", Issuer "RapidSSL RSA CA 2018" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id A088585A50 for ; Fri, 8 Jun 2018 14:46:11 +0000 (UTC) (envelope-from chris@cretaforce.gr) Received: from smtp3.cretaforce.gr (smtp3.cretaforce.gr [78.47.184.71]) by smtpb4.cretaforce.gr (Postfix) with ESMTP id 361E820D06 for ; Fri, 8 Jun 2018 17:46:09 +0300 (EEST) Received: from server1.cretaforce.gr (server1.cretaforce.gr [138.201.248.69]) by smtp3.cretaforce.gr (Postfix) with ESMTP id 17E713E907 for ; Fri, 8 Jun 2018 17:46:00 +0300 (EEST) Received: from [192.168.2.3] (athedsl-4449129.home.otenet.gr [79.129.211.89]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) (Authenticated sender: chris@cretaforce.gr) by server1.cretaforce.gr (Postfix) with ESMTPSA id CFC2E2732E; Fri, 8 Jun 2018 17:45:59 +0300 (EEST) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.3 \(3445.6.18\)) Subject: Re: Toshiba disk low performance From: Christos Chatzaras In-Reply-To: Date: Fri, 8 Jun 2018 17:45:58 +0300 Cc: FreeBSD Content-Transfer-Encoding: quoted-printable Message-Id: <1DBCEF1D-DA0D-4B69-978F-1EAA5F4AE138@cretaforce.gr> References: <20180607171933.6b4babd094f4d056da797cf5@sohara.org> <5D96200B-649B-4851-9FC6-F56F3188326B@cretaforce.gr> <18DD35BD-0DA5-4186-9633-F9270744F9AD@cretaforce.gr> To: Daniel Feenberg X-Mailer: Apple Mail (2.3445.6.18) X-CretaForce-MailScanner-Information: Please contact the ISP for more information X-CretaForce-MailScanner-ID: 17E713E907.A0E2C X-CretaForce-MailScanner: Found to be clean X-CretaForce-MailScanner-From: chris@cretaforce.gr X-Spam-Status: No 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 14:46:12 -0000 I run these benchmark tests in Linux which show slow random writes. I = don't think the issue is related to FreeBSD. > On 8 Jun 2018, at 17:02, Daniel Feenberg wrote: >=20 >=20 >=20 > On Fri, 8 Jun 2018, Christos Chatzaras wrote: >=20 >> I did some benchmarks and the problem exist in both Linux and = FreeBSD. >>=20 >> I benchmark a server with Toshiba disks and a server with Seagate = disks. >>=20 >> First I install debian without RAID-1. Then I install iozone. >>=20 >> Tests done with hdparm to test disk bandwidth and iozone to test = random read/writes. >>=20 >> Here are the results: >>=20 >> https://hastebin.com/gayidosaju.pas >>=20 >> As you can see the bandwidth for the Toshiba disks is slower than = Seagate but this doesn't really matter. >>=20 >> 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. >>=20 >> That's why the issue happens mostly during a "mysql import" and not = other server tasks. >=20 > 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? >=20 > Daniel Feenberg > _______________________________________________ > freebsd-questions@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to = "freebsd-questions-unsubscribe@freebsd.org"