Date: Fri, 3 Jan 2014 09:29:52 +0100 From: Andrea Brancatelli <abrancatelli@schema31.it> To: freebsd-virtualization@freebsd.org Subject: Re: Real Device with BHyve Message-ID: <CADfWLemHj4mP37sUAmZ4F4QxsuS4dVFs14=3D0x3Tb-cvz=QgQ@mail.gmail.com> In-Reply-To: <52C5CC18.90105@mail.lifanov.com> References: <mailman.314.1388694128.1399.freebsd-virtualization@freebsd.org> <52C5CC18.90105@mail.lifanov.com>
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Forgive me, but I can't understand what you mean. Are we talking of using something like /dev/cciss (just to say...) instead of /dev/da2 as the device shared with the VM? Won't the VM and the real system clash in using the same device? On Thu, Jan 2, 2014 at 9:29 PM, Nikolai Lifanov <lifanov@mail.lifanov.com>w= rote: > On 01/02/14 15:22, freebsd-virtualization-request@freebsd.org wrote: > > Hello everybody. > > > > I'm doing some experiments with bhyve on 10.0-RC3 and I got stuck at a > > certain point. > > > > I was trying to have a VM use a direct device (/dev/da2) instead of a > disk > > image. I was trying it in order to understand if there was any real > > performance difference between using a raw drive or an image-disk on th= e > > same drive. > > > > Well, the machine starts ok but when the "child" FreeBSD starts > > installation something strange happens. When I get to the partitioning > > screen I can see the device avaiable as /dev/vtdb0 with the correct siz= e > > and such. I choose autopartitioning, the installer writes the partition > > table but when it start to write /dev/vtdb0p2 a very cryptic error > appears > > about being unable to write - sorry, did not write it down. > > > > The installer then stops. > > > > If I do a fdisk /dev/vtdb0 in the VM I can see the GPT partition being > > there. If I do a fdisk /dev/da2 on the host machine, I can see the GPT > > partition as well, but the VM just doesn't want to write on it. > > > > I even tried changing kern.geom.debugflags=3D16 as I thought the host > machine > > could be locking somehow the drive, but that didn't seem to make any > > difference. I know it was a lame check but I was out of ideas. > > > > So I just wanted to understand if such a scenario is supposed to be > > supported.... > > > > What I was thinking of, for example, was of having an external iSCSI > device > > connected on the hostmachine mapped as a virtual disk for a specific VM= , > in > > order to speed the VM disk performances. > > > > > > Just another quick question... I have seen some improvements by having > the > > VM's virtual disk on ZFS against UFS. Is it just me or is there any rea= l > > improvement by using ZFS? > > > > Thanks a lot. > > > > > > -- *Andrea BrancatelliSchema 31 S.r.l. - Socio UnicoResponsabile ITROMA > > - FIRENZE - PALERMO ITALYTel: +39. 06.98.358.472* *Cell: +39 > > 331.2488468Fax: +39. 055.71.880.466Societ? del Gruppo SC31 ITALIA* > > I'm not answering your question precisely, but can you pass through the > disk controller to the virtual machine instead? I also know that zvol > and iscsi backends work, at least the last time I checked. > > - Nikolai Lifanov > _______________________________________________ > freebsd-virtualization@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-virtualization > To unsubscribe, send any mail to " > freebsd-virtualization-unsubscribe@freebsd.org" > --=20 *Andrea BrancatelliSchema 31 S.r.l. - Socio UnicoResponsabile ITROMA - FIRENZE - PALERMO ITALYTel: +39. 06.98.358.472* *Cell: +39 331.2488468Fax: +39. 055.71.880.466Societ=C3=A0 del Gruppo SC31 ITALIA*
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