From owner-freebsd-stable@FreeBSD.ORG Tue Oct 13 17:57:39 2009 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id E8B7F1065679 for ; Tue, 13 Oct 2009 17:57:39 +0000 (UTC) (envelope-from ivoras@gmail.com) Received: from mail-ew0-f218.google.com (mail-ew0-f218.google.com [209.85.219.218]) by mx1.freebsd.org (Postfix) with ESMTP id 4FEC28FC15 for ; Tue, 13 Oct 2009 17:57:38 +0000 (UTC) Received: by ewy18 with SMTP id 18so4021536ewy.43 for ; Tue, 13 Oct 2009 10:57:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:from:date:x-google-sender-auth:message-id:subject:to:cc :content-type:content-transfer-encoding; bh=J1wthPXcfq7GfEWDG7Na9LwGtPbOxB4scKYyt6H31Lc=; b=j9Gn2JTZpJBOo8cB20W90VRmVQZY3Fck1SnjqDwaSCuddwG4gMrzXWgKSvGTIGVev3 CW8TzcHfCEaNm7XDoL+1c2LY9+a/NFqdsImr0YINmBk1uoF3UudbMi+W+tKi+aD7SqVN oiWuaaBnqYmGRxwTnpUS3D/vpTNaVaPC+Sut8= 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 :content-transfer-encoding; b=PiYkVaYEm5Fw7/dItdnmyGJhBr0yPO4SZWdTt+V9Wm0Zox2moy9qh3W0DnwxBxH5Id qiVZr3OTlqf+MjzDyXD8BSi4TnL4seDSULMJ4vbZh7K7orZIDcGZ2DROP8eBwd5AycRB yguzNTZL79rJGZhwNxH21fgX5jMc8NpdM7f7o= MIME-Version: 1.0 Sender: ivoras@gmail.com Received: by 10.216.91.69 with SMTP id g47mr2740888wef.167.1255456658242; Tue, 13 Oct 2009 10:57:38 -0700 (PDT) In-Reply-To: References: <9bbcef730910130633w150571a0k461fb4e67a51fb1d@mail.gmail.com> From: Ivan Voras Date: Tue, 13 Oct 2009 19:57:18 +0200 X-Google-Sender-Auth: 6aa25c7860a9fd9d Message-ID: <9bbcef730910131057i71db846et1f0d4aeadef5e302@mail.gmail.com> To: Larry Rosenman Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Cc: freebsd-stable@freebsd.org Subject: Re: Extreme console latency during disk IO (8.0-RC1, previous releases also affected according to others) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 13 Oct 2009 17:57:40 -0000 2009/10/13 Larry Rosenman : >>>> note huge packet loss. It looks like it's VM fault or something like i= t. >>> >>> It sounds like the VM is failing to execute the guest during certain >>> types of I/O. A bit of scheduler tracing in the host OS probably wouldn= 't go >>> amiss to confirm that the VM really is suspending the guest >> >> It's VMWare ESXi underneath, which is *Officially Not Linux* though some >> ducks may disagree - anyway, I suspect tracing the host in this way is n= ext >> to impossible without some kind of diamondium-level contract. >> > What information do you need? =C2=A0I have a platinum VMWare contract. > > What version of ESXi? Hi, It is ESXi 3.5 - but if the problem is really in ESXi I presume anyone could reproduce it. My setup is nothing special - Xeon 5405, 8 GB RAM, SATA drives on ICH9. As for what data is needed, it depends on what you can get - from this discussion thread it looks like it would be enough to verify that disk IO doesn't leave VM processes waiting (i.e. that disk IO doesn't interfere with CPU-bound or idle virtual machines). Though now when I think of it - doesn't Linux ATA driver poll IO in some funky way, expecting to get lower latency that way?