From owner-freebsd-virtualization@freebsd.org Sat Mar 19 03:46:30 2016 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 50EAEAD4C4C for ; Sat, 19 Mar 2016 03:46:30 +0000 (UTC) (envelope-from paul@redbarn.org) Received: from family.redbarn.org (family.redbarn.org [IPv6:2001:559:8000:cd::5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 437381970 for ; Sat, 19 Mar 2016 03:46:30 +0000 (UTC) (envelope-from paul@redbarn.org) Received: from [IPv6:2001:559:8000:cb:c459:3948:dd3b:ad1d] (unknown [IPv6:2001:559:8000:cb:c459:3948:dd3b:ad1d]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by family.redbarn.org (Postfix) with ESMTPSA id ED2551812B; Sat, 19 Mar 2016 03:46:28 +0000 (UTC) Message-ID: <56ECCB91.9080503@redbarn.org> Date: Fri, 18 Mar 2016 20:46:25 -0700 From: Paul Vixie User-Agent: Postbox 4.0.8 (Windows/20151105) MIME-Version: 1.0 To: "Russell L. Carter" CC: "freebsd-virtualization@freebsd.org" Subject: Re: UFS vs. ZFS inside bhyve hosted on ZFS References: <56ECAFEB.8060305@pinyon.org> In-Reply-To: <56ECAFEB.8060305@pinyon.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.21 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, 19 Mar 2016 03:46:30 -0000 Russell L. Carter wrote: > ... > So I am wondering if UFS in the -current guest might be better > overall. I can certainly do a multiple hour experiment, installing > a new guest with UFS root, but since I am new to this, perhaps there is > conventional wisdom about ZFS vs. UFS in the guest? Maybe UFS in the > guest requires less cpu resources from the host? Or not? i think you should do that experiment and share your results here. my similar experiment did not involve bhyve. i make a zvol and put a ufs inside, and mounted that. for writing, it was so much faster than raw zfs, that i wondered if i should start migrating other things to it. as two examples, postgres servers and MH "Mail" directories go really really fast in ufs-on-zvol compared to zfs. all my bhyve's are ufs, and their system disks are host zvols, not host zfs files made with "truncate". i admit that this was superstition on my part, but it's served me very well. one of my guests even expanded his bhyve file systems using geom and tunefs, after i made his zvol bigger. so, there's not much downside that i've seen. -- P Vixie