Date: Mon, 30 Dec 2013 17:48:21 +0100 From: Andrea Brancatelli <abrancatelli@schema31.it> To: freebsd-virtualization@freebsd.org Subject: Real Device with BHyve Message-ID: <CADfWLen8WsBHU51%2B8vU_71js3-DCFa13DTakbDLoWRmhAu6XHw@mail.gmail.com>
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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 the 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 size 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 machi= ne 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 real improvement by using ZFS? Thanks a lot. --=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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