From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id CCB231382C5 for ; Tue, 23 Jun 2020 16:14:39 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 05990E0907; Tue, 23 Jun 2020 16:14:34 +0000 (UTC) Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id AAE21E08BB for ; Tue, 23 Jun 2020 16:14:33 +0000 (UTC) Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailout.nyi.internal (Postfix) with ESMTP id 7831E5C02AC for ; Tue, 23 Jun 2020 12:14:32 -0400 (EDT) Received: from imap21 ([10.202.2.71]) by compute7.internal (MEProxy); Tue, 23 Jun 2020 12:14:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=aeam.us; h= mime-version:message-id:in-reply-to:references:date:from:to :subject:content-type; s=fm2; bh=JefZWv3Z52GODWPZuQcThd0d8WoS9ti r9mCXuyU5Hk4=; b=qZf2SWlMphn+wvLmPorLXMiszsWhk4tMplYQC8zqtDV/AEc xwC5K+aM4BML3EE8U/KzV9URY8NQdzVmbllZsdv85IXM7L49N3v/15q3Y9+Vqdpp HL/ckze/lMMWKuLxLnNCYU4KRZpECKq+gMDB4KKTEY8w529o0agX9ZiAEAh5doRA +9jP2OBVE14gsBeU9uCHeNMttA7jKZHEfIsNE1nKCg/G/PuGe2hs1Cb2hhdGXFIE 458wqP1o3Lkcl94D3bTRUPQFnfXZRgXwswebUrQLZ2xF1fcxAhscjzA4VQbUQQcl +42njgnRvfQV4RNJKqgN90bqTzQXuHca3Hk1GbQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=JefZWv 3Z52GODWPZuQcThd0d8WoS9tir9mCXuyU5Hk4=; b=pHjaerSWmFK6PdSB6Aoqfh n1+hyC3PvEQBHEavE33IUS6FzyBcUCuxNcv38OJhpOOjlRlCzTLfUEzYHRr3VSTa xj2PVslahYzoQ7QGlLr5wa/iReWuCk9s8cvbyyeLx+urAj02E1fquPUubTdLT5db qsqRZKuMGodNwHmcQPss2cnShgvagZS/V/dKR8DY5j7wdBj+zgYpQY/TUvlXjjSn cVdZCxuzZNAeUSbCkLTrZK8cVt3riJhGHp11ggDAQxEsNjxgnG+6yoaT1EtJ60Jv oVLVvMyS8SyU+z47Z3OMNVOcGGug/mJcgynPLY3xZPiaxqON+WX2XloGx5ZFYPDA == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduhedrudekhedgjeduucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefofgggkfgjfhffhffvufgtsehttd ertderredtnecuhfhrohhmpedfufhiugcuufhprhihfdcuoehsihgusegrvggrmhdruhhs qeenucggtffrrghtthgvrhhnpeeukeefkefggeejjeevkeegffdvgffgueetueefgeehje fhhfekfeejieevhfevleenucffohhmrghinhepfihikhhiphgvughirgdrohhrghenucev lhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehsihgusegrvg grmhdruhhs X-ME-Proxy: Received: by mailuser.nyi.internal (Postfix, from userid 501) id 366CE660085; Tue, 23 Jun 2020 12:14:32 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.3.0-dev0-543-gda70334-fm-20200618.004-gda703345 Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply Mime-Version: 1.0 Message-Id: <4f35306e-e509-4cae-907d-7eb026c008e9@www.fastmail.com> In-Reply-To: References: <6d77acb3-5754-06cb-b8ef-2f1a5d7d8084@gmail.com> <5EE8A6C9.9020900@youngman.org.uk> <5611481.lOV4Wx5bFT@lenovo.localdomain> Date: Tue, 23 Jun 2020 11:14:03 -0500 From: "Sid Spry" To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Testing a used hard drive to make SURE it is good. Content-Type: text/plain X-Archives-Salt: 399368fa-23f1-4af3-bcae-ed73c651fda8 X-Archives-Hash: 22fa4887d9416b82628ac952fa92d6a9 On Tue, Jun 16, 2020, at 7:25 AM, Rich Freeman wrote: > On Tue, Jun 16, 2020 at 7:36 AM Michael wrote: > > > > Just to add my 2c's before you throw that SMR away, the use case for these > > drives is to act as disk archives, rather than regular backups. You write > > data you want to keep, once. > > If your write pattern is more like a tape SMR should be ok in theory. > For example, if you wrote to a raw partition using tar (without a > filesystem) I suspect most SMR implementations (including > drive-managed) would work tolerably (a host-managed implementation > would perform identically to CMR). Once you toss in a filesystem then > there is no guarantee that the writes will end up being sequential. > > And of course the problem with these latest hidden SMR drives is that > they generally don't support TRIM, so even repeated sequential writes > can be a problem because the drive doesn't realize that after you send > block 1 you're going to send blocks 2-100k all sequentially. If it > knew that then it would just start overwriting in place obliterating > later tracks, since they're just going to be written next anyway. > Instead this drive is going to cache every write until it can > consolidate them, which isn't terrible but it still turns every seek > into three (write buffer, read buffer, write permanent - plus updating > metadata). If they weren't being sneaky they could have made it > drive-managed WITH TRIM so that it worked more like an SSD where you > get the best performance if the OS uses TRIM, but it can fall back if > you don't. Sequential writes on trimmed areas for SMR should perform > identically to writes on CMR drives. > So if I'm understanding properly most drive firmware won't let you operate the device in an append-only mode? If any do I suspect NILFS (https://en.wikipedia.org/wiki/NILFS) may be a good choice: "NILFS is a log-structured filesystem, in that the storage medium is treated like a circular buffer and new blocks are always written to the end. [...]" Realistically I don't know how maintained the filesystem is, and it may still enforce a hot and warm/cold data separation as a practical concern. As-is my intended use for these very large drives was not going to be for hot files anyway; spinning media is too slow. They were going to be running a snapshottable filesystem and would host my backups. But if I'm reading it right these drives just suck across the board? I'm confused. It's like they'd be good at one thing but then they tried to lie behind the scenes and ended up making the drives good at nothing.