From owner-freebsd-current@FreeBSD.ORG Sat Feb 14 17:14:32 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4BA7B106566B for ; Sat, 14 Feb 2009 17:14:32 +0000 (UTC) (envelope-from svein-listmail@stillbilde.net) Received: from mail.stillbilde.net (d80.iso100.no [81.175.61.195]) by mx1.freebsd.org (Postfix) with ESMTP id 7B4D98FC18 for ; Sat, 14 Feb 2009 17:14:31 +0000 (UTC) (envelope-from svein-listmail@stillbilde.net) Received: from [192.168.4.9] (unknown [192.168.4.9]) (Authenticated sender: svein) by mail.stillbilde.net (Familien Skogens mail) with ESMTPSA id 5A1EC39; Sat, 14 Feb 2009 17:11:11 +0000 (UTC) Message-ID: <4996FBF3.3040801@stillbilde.net> Date: Sat, 14 Feb 2009 18:14:27 +0100 From: "Svein Skogen (listmail account)" User-Agent: Thunderbird 2.0.0.19 (Windows/20081209) MIME-Version: 1.0 To: Scott Long References: <499551B9.7050805@samsco.org> In-Reply-To: <499551B9.7050805@samsco.org> X-Enigmail-Version: 0.95.7 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Cc: FreeBSD Current , FreeBSD Stable Subject: Re: HEADS UP: Major CAM performance regression X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 14 Feb 2009 17:14:32 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Scott Long wrote: > All, > > A major performance regression was introduced to the CAM subsystem in > FreeBSD 7.1. The following configurations are known to be affected: > > VMWare ESX > VMWare Fusion > (using bt or lsilogic controller options) > HP CISS RAID > Some MPT-SAS combinations with SATA drives attached > (Includes Dell SAS5/ir, but not PERC5/PERC6). > > Pure SCSI and SAS subsystems likely are NOT affected. Any hardware > that uses the 'ata' driver is also definitely NOT affected. To > determine if your installation is affected, run the following command as > root: > > camcontrol tags da0 > > Substitute 'da0' with another appropriate drive device number, if > needed. Note that this ONLY AFFECTS 'da' DEVICES. If your disks are > 'ad' devices, they are NOT affected. > > The result from running this command should be an output similar to the > following: > > (pass0:mpt0:0:8:0): device openings: 255 > > If, instead, it reports a value of '1', you are likely affected. Note > that it may be normal for USB memory devices to report a low number. > Also, many legacy SCSI disks, and devices that are not disks, may also > be expected to report a low number. > > The effect of this problem is that only one I/O command will be issued > to the controller and disk at a time, instead of overlapping multiple > commands in parallel. This causes significantly higher latency in > servicing moderate and heavy I/O workloads, leading to very poor > performance. Performance can be easily compared by downgrading to > FreeBSD 7.0. Any estimate on when this will be MFC'ed down to RELENG_7 yet? //Svein - -- - --------+-------------------+------------------------------- /"\ |Svein Skogen | svein@d80.iso100.no \ / |Solberg Østli 9 | PGP Key: 0xE5E76831 X |2020 Skedsmokorset | svein@jernhuset.no / \ |Norway | PGP Key: 0xCE96CE13 | | svein@stillbilde.net ascii | | PGP Key: 0x58CD33B6 ribbon |System Admin | svein-listmail@stillbilde.net Campaign|stillbilde.net | PGP Key: 0x22D494A4 +-------------------+------------------------------- |msn messenger: | Mobile Phone: +47 907 03 575 |svein@jernhuset.no | RIPE handle: SS16503-RIPE - --------+-------------------+------------------------------- Picture Gallery: https://gallery.stillbilde.net/v/svein/ - ------------------------------------------------------------ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkmW+/IACgkQODUnwSLUlKTVuACgpk70v7d6hyBmvIdaFhLsDA01 nqIAoJkljSXU+TRb7tl9xM8EEerFeMGz =0mNQ -----END PGP SIGNATURE-----