From nobody Fri Oct 28 00:36:59 2022 X-Original-To: questions@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 4Mz3XQ1Kvdz4gbRd for ; Fri, 28 Oct 2022 00:37:10 +0000 (UTC) (envelope-from dpchrist@holgerdanske.com) Received: from holgerdanske.com (holgerdanske.com [184.105.128.27]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "holgerdanske.com", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Mz3XP181Tz3fLh for ; Fri, 28 Oct 2022 00:37:09 +0000 (UTC) (envelope-from dpchrist@holgerdanske.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=holgerdanske.com; s=nov-20210719-112354; t=1666917424; bh=uYn1arYfhW4hjXoKIXwG6/vutmlIjxVxD/35J6QUm84=; h=Received:Message-ID:Date:MIME-Version:User-Agent:Subject: Content-Language:To:References:From:In-Reply-To:Content-Type: Content-Transfer-Encoding; b=nMCAK2CzuQ7O5B/SkWcdh25aTi74w2h5SxgssfhWcnXGMDfRMorhJgI4BAyKkqGoD UEMn+ecr5viKrCUmqLbAQKUCvBuJ5/ipEUUtS8Cs3gEuzWXQS1CacyfyeGxmiGc1lN bHq7Xbncb/G3K5cP7Mz1S2bG4PLqu9Wqr6iWyN8VrSSUUPEpbs/aLuYaNB7pdSSV4F YbWk3yRa8E7s09w0jL+l4UZqq2JEtUVfFLCzS8HbzrcacaXbTfaFLkjUiAjEkir1kg vR+5qCLmzZZOWOac2VhNxKdyymkkGPFMWyAQpZpwO7qNgfL6x/DYpTB/eOj1SRn4mf 1+dy4iwJB0x+VL7Z+VSakQ3aVZBmrUyMGeazVDkyId9x+Oyhf10uvxLl5Tmr2BPAYL G/QkeoTs6cmam5iP4D49Va4/c13ne67LSFvEj55holbrerDGcmwJgt2p6BsHiFL5kH ejeqCfy6lo91ig0pFQ7WyUrbaG1lnV7j5Gs8BfPjFFYpnZX4gG0eQpDR9C9DYwtqcL +X9ZJsEHkUq/l7SnBZQK5fGGqWDYB1/O7dvh/B7TCHlrG/eI9OIbYTKkiFK7AH35XJ r7mrk8NdJEqzsRwAYBwxPm2pUZgKJcl9WD4/asMxQtKZFnu5/G34kSJBSFmTZYyp/g r8o1jsyqUDseXwNuCKEb0P0A= Received: from 99.100.19.101 (99-100-19-101.lightspeed.frokca.sbcglobal.net [99.100.19.101]) by holgerdanske.com with ESMTPSA (TLS_AES_128_GCM_SHA256:TLSv1.3:Kx=any:Au=any:Enc=AESGCM(128):Mac=AEAD) (SMTP-AUTH username dpchrist@holgerdanske.com, mechanism PLAIN) for ; Thu, 27 Oct 2022 17:37:04 -0700 Message-ID: <5561436c-dc6e-ecd1-8054-0f1ae2788d1f@holgerdanske.com> Date: Thu, 27 Oct 2022 17:36:59 -0700 List-Id: User questions List-Archive: https://lists.freebsd.org/archives/freebsd-questions List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-questions@freebsd.org X-BeenThere: freebsd-questions@freebsd.org MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.13.0 Subject: Re: Setting up ZFS L2ARC on a zvol Content-Language: en-US To: julio@meroh.net, "questions@freebsd.org" References: <052d0579-7343-4aa7-8e27-fdab0fe6f400@holgerdanske.com> From: David Christensen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4Mz3XP181Tz3fLh X-Spamd-Bar: --- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=holgerdanske.com header.s=nov-20210719-112354 header.b=nMCAK2Cz; dmarc=pass (policy=none) header.from=holgerdanske.com; spf=pass (mx1.freebsd.org: domain of dpchrist@holgerdanske.com designates 184.105.128.27 as permitted sender) smtp.mailfrom=dpchrist@holgerdanske.com X-Spamd-Result: default: False [-4.00 / 15.00]; NEURAL_HAM_SHORT(-1.00)[-1.000]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_LONG(-1.00)[-1.000]; DMARC_POLICY_ALLOW(-0.50)[holgerdanske.com,none]; R_DKIM_ALLOW(-0.20)[holgerdanske.com:s=nov-20210719-112354]; R_SPF_ALLOW(-0.20)[+a]; MIME_GOOD(-0.10)[text/plain]; MLMMJ_DEST(0.00)[questions@freebsd.org]; TO_DN_EQ_ADDR_SOME(0.00)[]; MIME_TRACE(0.00)[0:+]; FROM_EQ_ENVFROM(0.00)[]; ASN(0.00)[asn:6939, ipnet:184.104.0.0/15, country:US]; RCPT_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_SOME(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; DKIM_TRACE(0.00)[holgerdanske.com:+]; FROM_HAS_DN(0.00)[]; ARC_NA(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[questions@freebsd.org]; RCVD_TLS_ALL(0.00)[] X-ThisMailContainsUnwantedMimeParts: N On 10/27/22 07:06, julio@meroh.net wrote: > From: owner-freebsd-questions@freebsd.org on behalf of David Christensen >> On 10/26/22 06:32, julio@meroh.net wrote: >>> I'm considering using ZFS as well for the root file system (as a separate single-drive pool) in order to simplify admin operations: I want to host some VMs on the NVMe for speed, and using zvols will be very helpful as I don't have to come up with the partition sizes upfront. >> Testing on a VirtualBox VM, it looks like you cannot use a ZFS volume as >> a cache device for another ZFS pool: > The question is whether this behavior is intentional or a bug. It appears to me that the behavior is intentional on FreeBSD 12.3-R; but I am not a ZFS developer, just a user. AIUI 12.3-R uses ZFS on Linux code (ZoL). Perhaps you can get a better answer via that project: https://zfsonlinux.org/ AIUI FreeBSD 13.1-R uses OpenZFS code. If you are seeing the behavior on 13.1-R, perhaps you can get a better answer via that project: https://openzfs.org/wiki/Main_Page David