From owner-freebsd-hackers@freebsd.org Tue Sep 22 19:28:58 2015 Return-Path: Delivered-To: freebsd-hackers@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 272A3A07F26 for ; Tue, 22 Sep 2015 19:28:58 +0000 (UTC) (envelope-from wojtek@puchar.net) Received: from puchar.net (puchar.net [188.252.31.250]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "puchar.net", Issuer "puchar.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 8AD1A1E2F; Tue, 22 Sep 2015 19:28:57 +0000 (UTC) (envelope-from wojtek@puchar.net) Received: Received: from 127.0.0.1 (localhost [127.0.0.1]) by puchar.net (8.14.9/8.14.9) with ESMTP id t8MJSs4u005013 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 22 Sep 2015 21:28:54 +0200 (CEST) (envelope-from wojtek@puchar.net) Received: from laptop.wojtek.intra (localhost [127.0.0.1]) by laptop.wojtek.intra (8.15.2/8.15.2) with ESMTP id t8MJSpoH004308; Tue, 22 Sep 2015 21:28:51 +0200 (CEST) (envelope-from wojtek@puchar.net) Received: from localhost (wojtek@localhost) by laptop.wojtek.intra (8.15.2/8.15.2/Submit) with ESMTP id t8MJSj1a004305; Tue, 22 Sep 2015 21:28:45 +0200 (CEST) (envelope-from wojtek@puchar.net) X-Authentication-Warning: laptop.wojtek.intra: wojtek owned process doing -bs Date: Tue, 22 Sep 2015 21:28:45 +0200 (CEST) From: Wojciech Puchar X-X-Sender: wojtek@laptop.wojtek.intra To: deco33000 Jog cc: Julian Elischer , "freebsd-hackers@freebsd.org" Subject: Re: Virtual images and qemu In-Reply-To: <184701442916573@web12h.yandex.ru> Message-ID: References: <730481442868585@web10h.yandex.ru> <5600F6D4.5040007@freebsd.org> <184701442916573@web12h.yandex.ru> User-Agent: Alpine 2.20 (BSF 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (puchar.net [10.0.1.1]); Tue, 22 Sep 2015 21:28:55 +0200 (CEST) X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Sep 2015 19:28:58 -0000 > Now it is fully working. I switched to virtualbox and chose a nat paravirt network. anyway FreeBSD 10.2 works fine under qemu - both amd64 and i386. tested. Anyway i never used qcow2 images, always raw. > I really hate virtualization but will bear with it anyway. instead of hate it's better to understand. Cases where virtualization is useful: - quick test of operating system (probably your case) - OS/kernel development - avoids reboot as well as provide freeze and memory dump. - when you have to run more than 1 different OS on one machine. For example: FreeBSD server but needs to run some server software under windows. Run windows virtual machine on this server with this software in it. - preparing software disk image for different architecture (often used be me for FreeBSD/mips, qemu on fast PC runs faster than actual machine and it's easier). - recovery of data from disks or disk images - may be few more. Cases where it is not useful, or suboptimal: - running multiple images of same unix system (eg. FreeBSD, linux) on one computer. Use jails or similar mechanism under other unix-alike. - magic way to enhance security. No it isn't. - running windows desktops for terminal systems, one virtual machine per user. Suboptimal and costly, run multiple users on single windows computer. - REALLY lots of other uses just because virtualization is popular. Virtualbox is MUCH faster, qemu is much more universal. Virtualization always make performance overhead, and always bigger than authors claim. Still - it is much better running some software set even with 50% overhead, than buying separate machine that would be 1% utilized.