From owner-freebsd-emulation@FreeBSD.ORG Thu Aug 7 21:27:50 2014 Return-Path: Delivered-To: emulation@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 3726FD44 for ; Thu, 7 Aug 2014 21:27:50 +0000 (UTC) Received: from mail-pd0-x22b.google.com (mail-pd0-x22b.google.com [IPv6:2607:f8b0:400e:c02::22b]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 0E79A2904 for ; Thu, 7 Aug 2014 21:27:50 +0000 (UTC) Received: by mail-pd0-f171.google.com with SMTP id z10so5868514pdj.30 for ; Thu, 07 Aug 2014 14:27:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=xn8MMoLuRrhO26vd5GGEl3CqeH/C+HuqT23BU7l3T7I=; b=kTSnw4xPMMB+xY55x9k5q2Wr6RyGPKbxJqfd7eVlinBa19HNo8ALVRXkGo5b/04mjO 6JpnKfxnuFJYjPgxDp1swERicDL8HtVRoC6K2ABBttRMKRSsLpgASZ2rcA/NSPIZxjV2 VEzmoHl0QVoQT7gDYFgcIRALA6Kp/tIDisqvT6+0muBOYtoStlvdo6ohwbhUY0mdiDPR 8KHoBUa5e7cB1RLnCD/XbkXNEiy+gM/UytSEA/qkhUVM/NTRpy9pe85bYQy5Da/hrO4u NjiqzpbtZ4yM7elvwG5t1izk0D/s3I5bCJcqoIDxsThCN0zFdrORC+AmNLScvGOszTgm 1V8w== MIME-Version: 1.0 X-Received: by 10.69.18.203 with SMTP id go11mr4555701pbd.50.1407446869707; Thu, 07 Aug 2014 14:27:49 -0700 (PDT) Received: by 10.70.118.132 with HTTP; Thu, 7 Aug 2014 14:27:49 -0700 (PDT) In-Reply-To: <53E3EA14.2060902@sentex.net> References: <53E3C33E.5030004@sentex.net> <53E3EA14.2060902@sentex.net> Date: Thu, 7 Aug 2014 16:27:49 -0500 Message-ID: Subject: Re: Making disk IO place nicely in a guest (VirtualBox) From: Adam Vande More To: Mike Tancsa Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.18 Cc: "freebsd-emulation@freebsd.org" X-BeenThere: freebsd-emulation@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Development of Emulators of other operating systems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Aug 2014 21:27:50 -0000 On Thu, Aug 7, 2014 at 4:05 PM, Mike Tancsa wrote: > On 8/7/2014 4:53 PM, Adam Vande More wrote: > >> >> >> Is your swap device ZFS backed like a ZVOL or something? >> > > Hi Adam, > The hypervisor does indeed have swap on zfs. I will try > disabling swap in the guest. I am pretty sure the panic was due to the > guest hitting and stalling on swap inside the VM. The guest dmesg is > attached. > > There does not seem to be much memory pressure on the hypervisor. The > hypervisor disk is a little slow, as I am experimenting with hast to sync > across to another zfs box. However, thats only for a zfs volume that holds > the VM disk images. The OS is not "hastified" > > In the hypervisor > > # pstat -T > 284/514622 files > 51M/16384M swap space > > CPU: 2.6% user, 0.0% nice, 6.6% system, 1.7% interrupt, 89.1% idle > Mem: 191M Active, 277M Inact, 14G Wired, 25M Cache, 1618M Buf, 315M Free > ARC: 7831M Total, 491M MFU, 6986M MRU, 83M Anon, 39M Header, 232M Other > Swap: 16G Total, 51M Used, 16G Free > > The machine has 16G. Should I think of limiting ARC ? The error messages shown are classic swap on ZFS errors which is inherently unstable especially under high IO loads. -- Adam