From nobody Sat Nov 5 03:40:21 2022 X-Original-To: freebsd-fs@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4N43DN6ydbz4hXhL for ; Sat, 5 Nov 2022 03:40:36 +0000 (UTC) (envelope-from asomers@gmail.com) Received: from mail-vk1-f181.google.com (mail-vk1-f181.google.com [209.85.221.181]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1D4" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4N43DM2tTbz3cdw for ; Sat, 5 Nov 2022 03:40:35 +0000 (UTC) (envelope-from asomers@gmail.com) Received: by mail-vk1-f181.google.com with SMTP id i15so3568389vka.0 for ; Fri, 04 Nov 2022 20:40:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=36OQmlXigsN7bdSWtwaufTyIcQhk1GLyLm2nDpV9cT4=; b=GvnLHsq+oliAjrkO9kfcgcBdc5pZSzUUpLB8aRbr9jgnm+eT7bSTsPBZ6vd73HBAC4 tpNFztKzLDPwFSUQ1zNJEWLI+jlZMiYM3czkUJHB/SjjOIxp1AXClCI98jRZhNHPGqSm WsHgo+vFzVKeDN6NH3uO9I7zpOr8vTDGfNdhRYPoLTle7Qqdw72sMASf75EpRtKIKqmJ tCMsI9ainaaAEU3zuoDuyJquMi4SufgmsX/nHMkymCjzKU2Q/UCuHYEFoiMIF/Xx5fs0 1sZHXJBV9vkGTeSiO9M9R+Be7yKy6yxP+TTsWd9YROZo38tyZZ+TL6860swv0skA8IlL fFGQ== X-Gm-Message-State: ACrzQf13Ajyln+23vyTOD4ZzUkxlWdK9t3Y/zTYYWV3xypK2VrCeCvCO B27Wh/rowRJtnw81K0E2FOnpwB7R8s8YPFHYc99Hpwgd X-Google-Smtp-Source: AMsMyM7V8XB8Qp22iQjZG4Dr+ISxKSHlGY4hkyfQzgD3vJ0A5bXbHvbC55Kwluqw3SMtOJTGufgK+g6so7X890kZoP0= X-Received: by 2002:a1f:9d82:0:b0:3ab:1049:dbfb with SMTP id g124-20020a1f9d82000000b003ab1049dbfbmr21946192vke.34.1667619634043; Fri, 04 Nov 2022 20:40:34 -0700 (PDT) List-Id: Filesystems List-Archive: https://lists.freebsd.org/archives/freebsd-fs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-fs@freebsd.org MIME-Version: 1.0 References: In-Reply-To: From: Alan Somers Date: Fri, 4 Nov 2022 21:40:21 -0600 Message-ID: Subject: Re: zfs compression on a volume To: freebsd-fs Content-Type: multipart/alternative; boundary="000000000000e861e105ecb0f3e0" X-Rspamd-Queue-Id: 4N43DM2tTbz3cdw X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of asomers@gmail.com designates 209.85.221.181 as permitted sender) smtp.mailfrom=asomers@gmail.com X-Spamd-Result: default: False [-2.99 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.99)[-0.995]; FORGED_SENDER(0.30)[asomers@freebsd.org,asomers@gmail.com]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; RCVD_IN_DNSWL_NONE(0.00)[209.85.221.181:from]; RCVD_COUNT_TWO(0.00)[2]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; R_DKIM_NA(0.00)[]; MLMMJ_DEST(0.00)[freebsd-fs@freebsd.org]; RWL_MAILSPIKE_POSSIBLE(0.00)[209.85.221.181:from]; MIME_TRACE(0.00)[0:+,1:+,2:~]; RCVD_TLS_LAST(0.00)[]; TO_DN_ALL(0.00)[]; DMARC_NA(0.00)[freebsd.org]; FROM_HAS_DN(0.00)[]; FREEFALL_USER(0.00)[asomers]; FREEMAIL_ENVFROM(0.00)[gmail.com]; FROM_NEQ_ENVFROM(0.00)[asomers@freebsd.org,asomers@gmail.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; ARC_NA(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[freebsd-fs@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; TO_DOM_EQ_FROM_DOM(0.00)[] X-ThisMailContainsUnwantedMimeParts: N --000000000000e861e105ecb0f3e0 Content-Type: text/plain; charset="UTF-8" The cycles are wasted because the data is incompressible. On Fri, Nov 4, 2022, 8:21 PM void wrote: > Hi fs@ > > If a vm is created in bhyve on a freebsd host, and that vm is > zvol-backed, and the guest itself is encrypted with for > example lukfs(?) if it's linux, if the zvol compression > is set to for example zstd, does the vol get compressed, > or are cycles wasted compressing the uncompressible? > > TIA, > > --000000000000e861e105ecb0f3e0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
The cycles are wasted because the data is incompress= ible.

On Fri, Nov 4, 2022, 8:21 PM void <voi= d@f-m.fm> wrote:
Hi fs@

If a vm is created in bhyve on a freebsd host, and that vm is
zvol-backed, and the guest itself is encrypted with for
example lukfs(?) if it's linux, if the zvol compression
is set to for example zstd, does the vol get compressed,
or are cycles wasted compressing the uncompressible?

TIA,

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