From owner-freebsd-fs@freebsd.org Sat Jan 19 19:40:21 2019 Return-Path: Delivered-To: freebsd-fs@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 C52941490B49 for ; Sat, 19 Jan 2019 19:40:21 +0000 (UTC) (envelope-from ira@wakeful.net) Received: from mail-it1-x135.google.com (mail-it1-x135.google.com [IPv6:2607:f8b0:4864:20::135]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id A25556B190 for ; Sat, 19 Jan 2019 19:40:20 +0000 (UTC) (envelope-from ira@wakeful.net) Received: by mail-it1-x135.google.com with SMTP id m62so11466019ith.5 for ; Sat, 19 Jan 2019 11:40:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wakeful-net.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=SnRQQz0R1xvlzr6CZOk0NqNjF6cquTm5Zk/lkOKZhfk=; b=AouLRobbCfLWNdax1u/PcFH/hSAJU76Yutq6bAYbxt7UTO69AbCTfROaxDFnim5hbo CRO57ewvJ3DPWDgnQqwGBlcW2pPqomc7C1/rNw3q8wwxXc4cYySC9ACVNnF7vx6ImC6j JO2O1nmhXqSsxvpHBIosuSIp/DdAr6GfauVhuMDBEiBVXjDC+fvw5X7JV7ZhffAlLjHn FeRmZLAasfaLsYC9C907lp4YAvy3j8atH4miwLHFVWay6cELuLkl2k6U1Xeu4krwRk8c 571vFCq6VlCJmaKOnxPHkcZ8pzS+YQiviWuBodq1J6LhRxddmFJhLfOV6kLXCE0uzeJu XnNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=SnRQQz0R1xvlzr6CZOk0NqNjF6cquTm5Zk/lkOKZhfk=; b=Jpu20KMTDHfVGy292Vz29xLM+/0KJ9vMvy4Gf/gxUMoV3orfH6ryLHTUhNcr6ndYx3 9Uo3/KBTjiNVJ5xFWqt1lRZR/HzTa+a3Vws7xQpxDcqkwe+PTSUhuNO64yslaDfq32sS wNjmxWCqx9tG6VbxqP/jWl7AWgSliDNJx1qHFPjUuokGgcbSE98YZ2+6Tf/2IodC/fJD KEUIruNlDJB7D5LtxNeZxesaqK2SGgH69CEyhl4Fus0jt40nPEVwria2V4zfaKB7iY6u YRgiHK97QDIQNfRMvtUlqbOMAFmY+iKmGO0PpCxhQqL5a8d/m9CJsgoQAqTj1v6JA60Y qNhA== X-Gm-Message-State: AJcUukeQ3Ti0VNhUff44P9BWv7wnoryHrpRnobcc2j23PT8CjjAznzPk PcUiT8g2Etsy1EZl4fjFMibhywnj+cdTd1OVqio4Z54R X-Google-Smtp-Source: ALg8bN4ziNPxUQIkWFTymJVOEedzRZw3LjdJTV6ZWLXxjNn4BtPjTXxf20VA7C7pAVE5aot6JTgR3sWry0WshJWCIeI= X-Received: by 2002:a24:7609:: with SMTP id z9mr15181975itb.66.1547926819710; Sat, 19 Jan 2019 11:40:19 -0800 (PST) MIME-Version: 1.0 References: <1180280695.63420.1547910313494.JavaMail.zimbra@gausus.net> <92646202.63422.1547910433715.JavaMail.zimbra@gausus.net> In-Reply-To: <92646202.63422.1547910433715.JavaMail.zimbra@gausus.net> From: Ira Cooper Date: Sat, 19 Jan 2019 14:40:08 -0500 Message-ID: Subject: Re: ZFS on Hardware RAID To: Maciej Jan Broniarz Cc: freebsd-fs@freebsd.org X-Rspamd-Queue-Id: A25556B190 X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=wakeful-net.20150623.gappssmtp.com header.s=20150623 header.b=AouLRobb X-Spamd-Result: default: False [-5.34 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; R_DKIM_ALLOW(-0.20)[wakeful-net.20150623.gappssmtp.com:s=20150623]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-fs@freebsd.org]; DMARC_NA(0.00)[wakeful.net]; TO_MATCH_ENVRCPT_SOME(0.00)[]; DKIM_TRACE(0.00)[wakeful-net.20150623.gappssmtp.com:+]; RCPT_COUNT_TWO(0.00)[2]; RCVD_IN_DNSWL_NONE(0.00)[5.3.1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; MX_GOOD(-0.01)[ASPMX.L.GOOGLE.COM,ALT2.ASPMX.L.GOOGLE.COM,ASPMX5.GOOGLEMAIL.COM,ALT1.ASPMX.L.GOOGLE.COM,ASPMX3.GOOGLEMAIL.COM,ASPMX2.GOOGLEMAIL.COM,ASPMX4.GOOGLEMAIL.COM]; R_SPF_NA(0.00)[]; NEURAL_HAM_SHORT(-0.55)[-0.550,0]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+,1:+]; RCVD_TLS_LAST(0.00)[]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; RCVD_COUNT_TWO(0.00)[2]; IP_SCORE(-2.48)[ip: (-8.13), ipnet: 2607:f8b0::/32(-2.37), asn: 15169(-1.83), country: US(-0.08)] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 19 Jan 2019 19:40:22 -0000 On Sat, Jan 19, 2019 at 11:43 AM Maciej Jan Broniarz wrote: > Hi, > > I want to use ZFS on a hardware-raid array. I have no option of making it > JBOD. I know it is best to use ZFS on JBOD, but > that possible in that particular case. My question is - how bad of an idea > is it. I have read very different opinions on that subject, but none of > them seems conclusive. > > Any comments and especially case studies are most welcome. > All best, > I've actually built Illumos based ZFS NAS systems based on raid controllers and non-raid controllers. If given the choice, I'd use non-raid controllers, today. (HBAs) Why? Because ZFS handles the "raid" layer well. The write back cache a RAID controller provides, isn't really needed with ZIL, nor desired. All a raid controller really brings in my experience is added operational complexity once you use good enough hardware, mainly good ZIL drives and HBAs. So it isn't really a "bad" idea, more just redundant, expensive and inconvenient. You could have good reasons to do it, like that the RAID controller is built into the motherboard etc. Just make sure your data integrity is #1. Writeback caches are properly battery protected, or not used. etc. Best, -Ira