From owner-freebsd-fs@freebsd.org Tue May 12 15:51:19 2020 Return-Path: Delivered-To: freebsd-fs@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 1F8212F2D16 for ; Tue, 12 May 2020 15:51:19 +0000 (UTC) (envelope-from asomers@gmail.com) Received: from mail-oi1-f181.google.com (mail-oi1-f181.google.com [209.85.167.181]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 49M2N60YqFz4PMP for ; Tue, 12 May 2020 15:51:17 +0000 (UTC) (envelope-from asomers@gmail.com) Received: by mail-oi1-f181.google.com with SMTP id o7so18650134oif.2 for ; Tue, 12 May 2020 08:51:17 -0700 (PDT) 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=dAbHg0q92kWC5CPU+u7gYFwv7H8RKqH7Rci+51SRnRw=; b=nU26WfIvKHBr0kw7yxcMzVSS9dduckeqvSEIfju2FaYt5ZiLDLL8LepiOP/O8Pw2X5 sygSA7roWXbusDuLjtleW80VO0rUgwFx9Warid2G76XdtNtDXyCUKnTAh9E31/E+XpmJ 3pPVqTCP3m8PC9Hj0jGhIvyZXhQb+Ac8hcPVMzNwKDMJ23f70AeFiOXhRlyczkghqCsj iZNXVjlNl125yNY2iqIooVgwbJFOGS1ezkeaUuRBwHq84LO46KcQE1DoXrxYGu+gd2PF u5qLtbomKVHtcYw023Jy7YYhw2Y5RXIbT06fSj9HK3taobnMlr+MtEVy1z77poeEzfCF FWuQ== X-Gm-Message-State: AGi0PuZSMowdzS6pw3yRbt4GGpuasEedpnRCIox1H7Iy6Mf+UJYOCZJw D+Ta/dnqsjYStPoLRV3zXJY9JF/vNBEAwbbkuBA= X-Google-Smtp-Source: APiQypLfYw+TBUK/VlqSl3E/o9Nz5fMNfFU61tJCAcV5EOtjY5q5JPo1vfiiaAIo1zjcXblxRku2mHbMpKtJskCG3r0= X-Received: by 2002:aca:bf09:: with SMTP id p9mr22087309oif.55.1589298674910; Tue, 12 May 2020 08:51:14 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Alan Somers Date: Tue, 12 May 2020 09:51:03 -0600 Message-ID: Subject: Re: RAID - hardware vs. ZFS To: "D'Arcy Cain" Cc: freebsd-fs X-Rspamd-Queue-Id: 49M2N60YqFz4PMP X-Spamd-Bar: - Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of asomers@gmail.com designates 209.85.167.181 as permitted sender) smtp.mailfrom=asomers@gmail.com X-Spamd-Result: default: False [-1.21 / 15.00]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.96)[-0.961,0]; FROM_HAS_DN(0.00)[]; R_SPF_ALLOW(-0.20)[+ip4:209.85.128.0/17:c]; NEURAL_HAM_LONG(-0.98)[-0.984,0]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-fs@freebsd.org]; DMARC_NA(0.00)[freebsd.org]; URI_COUNT_ODD(1.00)[3]; MIME_TRACE(0.00)[0:+,1:+,2:~]; TO_DN_ALL(0.00)[]; RCPT_COUNT_TWO(0.00)[2]; RCVD_IN_DNSWL_NONE(0.00)[181.167.85.209.list.dnswl.org : 127.0.5.0]; TO_MATCH_ENVRCPT_SOME(0.00)[]; IP_SCORE(-0.26)[ip: (-0.45), ipnet: 209.85.128.0/17(-0.39), asn: 15169(-0.42), country: US(-0.05)]; FORGED_SENDER(0.30)[asomers@freebsd.org,asomers@gmail.com]; RWL_MAILSPIKE_POSSIBLE(0.00)[181.167.85.209.rep.mailspike.net : 127.0.0.17]; R_DKIM_NA(0.00)[]; FREEMAIL_ENVFROM(0.00)[gmail.com]; ASN(0.00)[asn:15169, ipnet:209.85.128.0/17, country:US]; FROM_NEQ_ENVFROM(0.00)[asomers@freebsd.org,asomers@gmail.com]; RCVD_TLS_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.33 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 May 2020 15:51:19 -0000 These days you're probably better off with ZFS software RAID. It's fast enough (easily 1GB/s on most modern hardware), rebuilds much faster for mostly empty pools (though slower for mostly full pools), and handles hot swapping well. Unlike hardware RAID, ZFS RAID is robustly protected by a Merkle hash tree of the entire file system, so undetected corruption is virtually impossible. And most importantly, the code is accessible and open source, so problems can be fixed. I haven't heard of any serious ZFS RAID bugs, but even if one pops up it is at least possible to fix it. That's not the case with HW RAID. I've heard of multiple commercial projects that failed just because of bugs in the hardware RAID that the vendor couldn't or wouldn't fix. -Alan On Tue, May 12, 2020 at 9:46 AM D'Arcy Cain wrote: > I have to purchase new servers soon. I am planning on getting Proliant > DL360 servers. These come with hardware RAID. I was wondering what > opinions people had about hardware RAID vs. using ZFS for RAID. Is one > safer than the other? What about performance? What about hot swapping? > > All opinions welcome. > > -- > D'Arcy J.M. Cain | Democracy is three wolves > http://www.druid.net/darcy/ | and a sheep voting on > +1 416 788 2246 (DoD#0082) (eNTP) | what's for dinner. > IM: darcy@VybeNetworks.com, VoIP: sip:darcy@druid.net > >