From owner-freebsd-virtualization@freebsd.org  Wed Sep  7 04:42:12 2016
Return-Path: <owner-freebsd-virtualization@freebsd.org>
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 4225DBC6917
 for <freebsd-virtualization@mailman.ysv.freebsd.org>;
 Wed,  7 Sep 2016 04:42:12 +0000 (UTC)
 (envelope-from FreeBSD@shaneware.biz)
Received: from ipmail06.adl2.internode.on.net (ipmail06.adl2.internode.on.net
 [150.101.137.129])
 by mx1.freebsd.org (Postfix) with ESMTP id C52BD7A4
 for <freebsd-virtualization@freebsd.org>; Wed,  7 Sep 2016 04:42:10 +0000 (UTC)
 (envelope-from FreeBSD@shaneware.biz)
Received: from ppp14-2-4-72.lns21.adl2.internode.on.net (HELO leader.local)
 ([14.2.4.72])
 by ipmail06.adl2.internode.on.net with ESMTP; 07 Sep 2016 14:07:00 +0930
Subject: Re: bhyve and dynamic allocation
To: Grzegorz Junka <list1@gjunka.com>
References: <862088a4-6934-4a03-cc1c-4b27154b9bb2@gjunka.com>
 <0553cd28-02da-ea34-19fc-340f8bfa6e23@freebsd.org>
Cc: freebsd-virtualization@freebsd.org
From: Shane Ambler <FreeBSD@ShaneWare.Biz>
Message-ID: <8034e078-1d5a-7269-428a-0155c4a271b2@ShaneWare.Biz>
Date: Wed, 7 Sep 2016 14:06:58 +0930
User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:45.0) Gecko/20100101
 Thunderbird/45.2.0
MIME-Version: 1.0
In-Reply-To: <0553cd28-02da-ea34-19fc-340f8bfa6e23@freebsd.org>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
X-BeenThere: freebsd-virtualization@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: "Discussion of various virtualization techniques FreeBSD supports."
 <freebsd-virtualization.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-virtualization>, 
 <mailto:freebsd-virtualization-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-virtualization/>
List-Post: <mailto:freebsd-virtualization@freebsd.org>
List-Help: <mailto:freebsd-virtualization-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-virtualization>, 
 <mailto:freebsd-virtualization-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 07 Sep 2016 04:42:12 -0000

On 07/09/2016 01:18, Peter Grehan wrote:
> Hi Grzegorz,
>
>> Is it possible / supported / planned to run a client OS without
>> specifying RAM/HDD up-front but with dynamically allocated resources?
>
>  The amount of RAM specified is just the maximum allowed, and by default
> is demand-paged without any pre-allocation.
>
>  For disk, the same effect can be achieved by using a sparse volume,
> e.g. 'truncate -s <disk-siz>' on UFS.
>

And if your using ZFS on the host you can create a sparse zvol with

zfs create -sV <disk-size> zpool/guestvol


-- 
FreeBSD - the place to B...Sharing Devices

Shane Ambler