From owner-freebsd-questions@freebsd.org Thu May 18 10:26:39 2017 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id CD2EAD707F4 for ; Thu, 18 May 2017 10:26:39 +0000 (UTC) (envelope-from mail@ozzmosis.com) Received: from homiemail-a56.g.dreamhost.com (sub5.mail.dreamhost.com [208.113.200.129]) (using TLSv1.1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id AFACD1A96 for ; Thu, 18 May 2017 10:26:39 +0000 (UTC) (envelope-from mail@ozzmosis.com) Received: from homiemail-a56.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a56.g.dreamhost.com (Postfix) with ESMTP id 284B06004916; Thu, 18 May 2017 03:26:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=ozzmosis.com; h=date:from :to:cc:subject:message-id:references:mime-version:content-type :in-reply-to; s=ozzmosis.com; bh=5smXLTHq867Fy69ZprpdMzyJQX0=; b= ydqiUtIt66x9LNlfj1KOixbKazX5qIvd5S+/MpIFIe86wKO/H5S1sttByABLUDTN 0pccYe0rNhXbcxiQRXyY0v/lJnWGboKdDtnOA0aQxqdOwuDSsvC46nTdeG75nbWN LzPbrYSzpQYyqHF8obM57l6V4c6jEaalaT82pdzykqg= Received: from blizzard.ozzmosis.com (203-214-44-104.dyn.iinet.net.au [203.214.44.104]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: relay@ozzmosis.com) by homiemail-a56.g.dreamhost.com (Postfix) with ESMTPSA id D702F6004911; Thu, 18 May 2017 03:26:32 -0700 (PDT) Received: by blizzard.ozzmosis.com (Postfix, from userid 1001) id EE358D82; Thu, 18 May 2017 20:26:29 +1000 (AEST) Date: Thu, 18 May 2017 20:26:29 +1000 From: andrew clarke To: Aaron Cc: freebsd-questions@freebsd.org Subject: Re: ZFS root on single SSD? Message-ID: <20170518102629.jtdoihm7aw2a5jjt@ozzmosis.com> References: <20170516222456.q3wuwlthgpoup7md@ozzmosis.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170428 (1.8.2) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 May 2017 10:26:39 -0000 On Tue 2017-05-16 16:00:15 UTC-0700, Aaron (drizzt321@gmail.com) wrote: > I think most modern SSDs have pretty good checks because of how they use > MLC/TLC NAND and how it fails. The biggest thing I can think of is a > controller/board failure, rather than suddenly having massive number of > blocks fail. However, it is a point that without copies=2 (or more) while > bit-rot/corruption would be detectable, it wouldn't be possible to > re-construct the bad blocks. Hmm, yes. How likely is a controller board failure, though? No more likely than a HDD controller failure, I'd have thought. > Side note, copies=2 resiliency test ( > http://jrs-s.net/2016/05/09/testing-copies-equals-n-resiliency/), rather > interesting, although I probably won't be using it, at least not for an SSD. Ah, this is something I was wanting to experiment with for a few years but never got around to it. The only difference was I would've written the file corruption program in Python! :-) Good stuff. Regards Andrew