From owner-freebsd-virtualization@freebsd.org Sat Aug 1 17:14:12 2015 Return-Path: Delivered-To: freebsd-virtualization@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 231A89B0798 for ; Sat, 1 Aug 2015 17:14:12 +0000 (UTC) (envelope-from nvass@gmx.com) Received: from mout.gmx.net (mout.gmx.net [212.227.15.18]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mout.gmx.net", Issuer "TeleSec ServerPass DE-1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 9D75868 for ; Sat, 1 Aug 2015 17:14:11 +0000 (UTC) (envelope-from nvass@gmx.com) Received: from moby.local ([79.107.15.195]) by mail.gmx.com (mrgmx002) with ESMTPSA (Nemesis) id 0LngNT-1YfLRk03u3-00hwBd for ; Sat, 01 Aug 2015 19:14:03 +0200 From: Nikos Vassiliadis Subject: hot-plugging disks to a VM To: "freebsd-virtualization@freebsd.org" Message-ID: <55BCFE13.2070501@gmx.com> Date: Sat, 1 Aug 2015 20:12:51 +0300 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:KXN6Aat/e5sBDYnmxpg8IXirA5nx0ELi100kkH/ANFEgxCHbGcR kbFoZlvUxAZg5UWHXGTq9QTgxyPE3kxsJJXj4Ow7T6eVrt26ZngIYVTNnOvdqLqyqDG2QfI rQmR4M90TR62jKBYzQTMSUl55IOx8uKpdef9C5S1S0IieipbGRzYtO4H/+QPz+wpIHahCjW OKpZm0QOjCrNu4kbsx6ZQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:e7UXpyYNQAc=:23rIxLOLaHmHLQMyb2cCMt ucOcMhEys90SEz+G7BjiwKfIgnCzn474pCQWzt+Ylwk0WUv8k99K1vqs7ClzYL8j4FGSB4ZHC XlZTp1egcEG1TE6+FeX23DXO+EifpeOrr0gqgwXkaEYScONZ1sB38DeZX06aiKLrZrueocLW7 eZ1XAtSiHcqRIs5qrWG9Zdz8nDnqWZQ+tYMOt87pQchec86Hn30vt7oA04Tk8ModBDBZhrG5n KfUa4CRnhGBLqbrS5VncJhOKEm2WivMtzrubLhF3sQyQoF2+mECA29jQNpT9ipj5hKelOyoVZ 3w0N3GBs+TlDb4i7n23eVwvjyL3KpUeq8Fssq/izBWsDelfeoJuqMMwgWEf6gSgSHpQwBEjmc 2OlMiuS9auVl+A+GZm2ZDEzMaIeEacHaMkdehh87fj3kZAD/dqzCbWZPRqbILTqFOiUG5HQGJ l1+GxKeAfWxp4m4kQnuV6WTEjIfOylVmkriLg5OVA89/8APm285IlW5SUrENeF3Q/WlmAzyLV HHLKjcBGaWGJN6+6Y3KnxkXhqMCcxjwWsBx9uIzkfGsDTEQ07bDmlhR8WkoO+XXCwinxzG9lA a6OKm7/zi91jI2R9TPaHVbW3hVuv4jv7RE9k44M6IHPVj9rg0FuIUPWgZlEMeDd5xW8QoUCkH Hzk2GYQBkgxueSQHgFPX7s6oLH7RfVlyThnGibSh3vqrOsc8kKTEXRavR/c2jxRKajmU= X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 01 Aug 2015 17:14:12 -0000 Hi, I was thinking of creating a HAST disk and using that as second disk to a VM. It seems that when the backing file is gone and returned, it's never re-opened. Is this scenario possible? Host machine: > root@moby:~/VMs # diskinfo /dev/hast/shared > /dev/hast/shared 512 21474830848 41943029 0 0 and from withing the VM: > root@lamb:~ # diskinfo /dev/vtbd2 > /dev/vtbd2 512 21474830848 41943029 0 0 > root@lamb:~ # file -s /dev/vtbd2 > /dev/vtbd2: Unix Fast File system [v2] (little-endian) last mounted on /mnt, last written at Sat Aug 1 19:33:17 2015, clean flag 0, readonly flag 0, number of blocks 5242878, number of data blocks 5076797, number of cylinder groups 33, block size 32768, fragment size 4096, average file size 16384, average number of files in dir 64, pending blocks to free 0, pending inodes to free 0, system-wide uuid 0, minimum percentage of free blocks 8, TIME optimization Then I go to the host, destroy /dev/hast/shared and re-create it. The VM is not able to use the disk anymore: > root@lamb:~ # file -s /dev/vtbd2 > vtbd2: hard error cmd=read 0-255 > /dev/vtbd2: ERROR: cannot read `/dev/vtbd2' (Input/output error) Is this possible? Can I somehow achieve hot-plugging a disk? Thanks for any thoughts, Nikos