From owner-freebsd-virtualization@freebsd.org Tue Mar 19 02:46:41 2019 Return-Path: Delivered-To: freebsd-virtualization@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 71103153A5EC for ; Tue, 19 Mar 2019 02:46:41 +0000 (UTC) (envelope-from vas@mpeks.tomsk.su) Received: from admin.sibptus.ru (admin.sibptus.ru [IPv6:2001:19f0:5001:21dc::10]) (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 A49FA8E473 for ; Tue, 19 Mar 2019 02:46:40 +0000 (UTC) (envelope-from vas@mpeks.tomsk.su) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sibptus.ru; s=20181118; h=Message-ID:Subject:To:From:Date:In-Reply-To; bh=JdKe2TYUcbcASPvurfcBUEw9d+8KaN7PYbtLGqrCQME=; b=kMAQPTNHjKIYJ1+ZIWjd5VanS3 v+STZSW5bfjpwmEFQ/HVcuXODguQJZbejsXlpQL7bba6IruXYTLd7WkD5jq2IAkqigiQlDzcvlmWe vroc8HEOH0XUHMq/YqMZtMbIPmIIo/QsmZrEU6AgKiMscOnOf2jNuJwJoHOBO0yJDokY=; Received: from vas by admin.sibptus.ru with local (Exim 4.92 (FreeBSD)) (envelope-from ) id 1h64ly-0002HY-UA for freebsd-virtualization@freebsd.org; Tue, 19 Mar 2019 09:46:38 +0700 Date: Tue, 19 Mar 2019 09:46:38 +0700 From: Victor Sudakov To: freebsd-virtualization@freebsd.org Subject: bhyve and vfs.zfs.arc_max, and zfs tuning for a hypervisor Message-ID: <20190319024638.GA8193@admin.sibptus.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="bg08WKrSYDhXBjb5" Content-Disposition: inline X-PGP-Key: http://www.dreamwidth.org/pubkey?user=victor_sudakov X-PGP-Fingerprint: 10E3 1171 1273 E007 C2E9 3532 0DA4 F259 9B5E C634 User-Agent: Mutt/1.11.3 (2019-02-01) Sender: Victor Sudakov X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.29 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: Tue, 19 Mar 2019 02:46:41 -0000 --bg08WKrSYDhXBjb5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Dear Colleagues, I have a FreeBSD 11.2 system with 32G RAM which I'm going to use as a bhyve host with zvols and sparse zvols, with (almost) no services/daemons of its own.=20 Could you please clarify some points for me? 1. Does ARC actually cache zfs volumes (not files/datasets)? 2. If ARC does cache volumes, does this cache make sense on a hypervisor, because guest OSes will probably have their own disk cache anyway. 3. Would it make sense to limit vfs.zfs.arc_max to 1/8 or even less of total RAM, so that most RAM is available to guest machines? 4. What other zfs tuning measures can you suggest for a bhyve hypervisor? --=20 Victor Sudakov, VAS4-RIPE, VAS47-RIPN 2:5005/49@fidonet http://vas.tomsk.ru/ --bg08WKrSYDhXBjb5 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJckFgOAAoJEA2k8lmbXsY0A24H/3GW0qbH0lZ2em6XApGBXBqX pid3dfr2kBGoNLNlMhdcJgGE1uyouVIfFTrq+rma4ZDE8jWmLd0OBIHLxSH6WvV4 0IoycEKUrJP59StI1zk8UCsBXDYplHxDEMsXGrsdbUFP4BET4r9K4E19vHBak8PQ eiXGEgjD3ctfV7AuaBBJnQqRBvfa+pTakmTqzv081YQFm6kF0DNph35YlLDEWRhv H+cv079/ckHUQl5G+WihmhlRaWYKsGRm7adhMw+BJbQJ0wZf9A3w5HXpvDh0rMYd SnjIqy5QCpqfsueHX0NIZrEMzacu0WnZ9NNRxDTSakMocm4Txdo43X5+YrhsWlE= =uMHF -----END PGP SIGNATURE----- --bg08WKrSYDhXBjb5--