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 61DE11382C5 for ; Tue, 23 Jun 2020 19:37:33 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 16DFDE0884; Tue, 23 Jun 2020 19:37:26 +0000 (UTC) Received: from mail-oi1-x231.google.com (mail-oi1-x231.google.com [IPv6:2607:f8b0:4864:20::231]) (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 A0FF6E079E for ; Tue, 23 Jun 2020 19:37:25 +0000 (UTC) Received: by mail-oi1-x231.google.com with SMTP id h17so2314730oie.3 for ; Tue, 23 Jun 2020 12:37:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:openpgp:autocrypt:message-id:date :user-agent:mime-version:in-reply-to; bh=r94lIT+fWPlWlDQHBj2dINKR/MMj8TfbFLoJSO+Lr0s=; b=t198ASbGOChcVLwnPs9J1imBYiFnZQOYjGiKpaaQDxEVpCCJinFTYcQ/0gfaD30VRL 4OFtZW2L9gHmSmhi+GEVMA+fhE9+DR3G2c7Zw0gNSozVsKlCmfFBJfVoaW2bpXNodkJi y430MkmGhxXpPuyqGcPJZs6NL6Jt8PfKpIwxtd9D6bC4tBOUJXauEeeLdhypp2Nougpv 5V3PN0RlxElIfLphivXEbEPoJIUc75AWVR/iW+lSMtVMkSnVyBzIKs8jF/6/yjaSqRKM bWx34ibUp8rmLTthLQwo9rLyBkcHTOcs35idSUbXw0OMS2wRtq1HhK2Nurwl69SoKm7H yjhQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:openpgp:autocrypt :message-id:date:user-agent:mime-version:in-reply-to; bh=r94lIT+fWPlWlDQHBj2dINKR/MMj8TfbFLoJSO+Lr0s=; b=LFmhscwXeu+sW49MViABabmJXOtZAdekG3LqnyljambxalE+UpPnXSxBQRIOwRihh9 7nver9EexXP3CXYZWVN7aq0OpKl+NMAEu167J5KGvVjxVlLcnVh0VBLI1EbXJfgBMxm6 n4BIJQvHr6stJhz//w++nVlY1LRx/x56gh87YiN/thBuvQAsaVaAqaZoeexfbUbcesXa NOxGSOirvdTagSmozlxEZLLw2lDFPUjxilRrY5ZKJJyLtONcQgs5dROjkFLe8WlMvxG2 wsEyaR3NlZtvHOIIGN32k0Ra6P+Rkm10IHlHWmtefDe/2jnVutXfAKc7kVNTWiK715uR n1Kg== X-Gm-Message-State: AOAM532F6QufWr6VhvLVf0bQxtfFIZiz/hb5z1O6Rk+As4soKJOgXTMr +mzqSMDgMr885diLDRReAkCbRmWg X-Google-Smtp-Source: ABdhPJzK0ynlaapgF/BuUcc1FbFv/Knz8aLr1FevkLTkiG9pMfbMsFtWAe7Ec0dI3i8KbtXgsrpVBQ== X-Received: by 2002:aca:d681:: with SMTP id n123mr17791834oig.82.1592941044685; Tue, 23 Jun 2020 12:37:24 -0700 (PDT) Received: from [192.168.0.100] (adsl-074-188-241-018.sip.asm.bellsouth.net. [74.188.241.18]) by smtp.gmail.com with ESMTPSA id o2sm4241712ota.14.2020.06.23.12.37.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 23 Jun 2020 12:37:23 -0700 (PDT) Subject: Re: [gentoo-user] Re: Testing a used hard drive to make SURE it is good. To: gentoo-user@lists.gentoo.org References: <6d77acb3-5754-06cb-b8ef-2f1a5d7d8084@gmail.com> <20200615231836.xje3kkkihsxrvhaz@grusum.endjinn.de> <158351d5-27cc-88d0-951c-893d0b5ad8aa@gmail.com> <1be400f1-9f5f-4e4a-ba8d-0fb7f8609a14@www.fastmail.com> <51f37de0-c955-c114-56bd-672a9e064e24@gmail.com> <27641ea5-ecc3-4e7c-a799-139680335d6b@www.fastmail.com> From: Dale Openpgp: preference=signencrypt Autocrypt: addr=rdalek1967@gmail.com; prefer-encrypt=mutual; keydata= mQINBFxc7MgBEAC+zrgEdqJJiDe/UDAB+ScmferXWfJTVjbVT2T4DQ7jiLrgP9aNUo1HioNF mrU3JPOCR32gvZyTbY1+niO5+VSo/+pSqQ785h6ZDj1klMkrg6tEzGnf2MNBpBj4houZwxQ+ WDKKTg2M9F+lv8wTIdR/JQn+hSviktLMtrghQlyLhpapsLXWLA6gMFebpQYwxUwemvan8ddX lQvJe9FGyFYvBi0dp1gl10F2O+DVZJxvX8xkX+yImVlhVJiC31gXHRcj+Qlo7gprlU7TIieF Uow6/ZvYKJ26pztVdFCg5w0rMJkF/x8Zd4A6wnuptiAPmWaQ1+YKgYDonbDUgwqFSx5/lN5z DGZ4LlioxeUTTPVvZsqBIeDz6jNFA583OYbo1/S26dqrvTFf2DKlsvoDpVfAhNlwJPjoixs0 X3FNqPv+M10n4kq5Iz7Q9E3O4s/nfFIYGocEslVka7zZPkXSaHbsn+KJlY8XV6qxtCEdh0/V XX1+1aU2J74M0JikWhpwxTZ1dP5aOyWSPPEgFFIRW6xwwC02SoRH9a7mggfGYp/YjPlONNaT SCL8sgRfvmq3D0XTbLyTjSbExxkfKDmbePQagawDE3TlI/oivHf1JaAcbwMb3LZuU4TGcOIl 5D+x7q0MUIeCop0ZFOwAnqW3AVVNvsBkv2KN+IHJryWAf0/iMQARAQABtBtEYWxlIDxyZGFs ZWsxOTY3QGdtYWlsLmNvbT6JAk4EEwEIADgWIQTZ7suruPBaS60bCYXvEM/XWu+ZnAUCXFzs yAIbIwULCQgHAgYVCgkICwIEFgIDAQIeAQIXgAAKCRDvEM/XWu+ZnN+7D/4/1dNG4aCz0+v+ 0dcjV5tY1feYEWCdHKyDzxWBxlCpd/0NPRQeNY4VMjbCl/sq7GkXi/c2SbfWDQ5BQRkkExG1 pSwuXSIehGok/4fpTi3HDAguRvzdCqlKPt7me05FyiC/WnpY5GOlJ3ruGw2qABv/RmV2q5b/ tkq7h1y1f16DTNr3/nsj8HzHcrHdXdL4kaYChSOe/dbQR9Stqak7eMyR+iwvrJMNF/CGl70P 2x5ybsXMDzRVOqNcpa5ZdhEMTVh6+vC1SOmm1BFMF8XCqBEvBbcHWDQmGYTdNCsS/ADm8CBl gvjJgLdIsAzoMu4WHQDFnzXAoArqFWgAf53isOS4AWrv29tF9b8Aa1vb7h5JEa+ArcMsA6Gl X38+GY6WXXaxKI9n3PTCWu9tPGnRh7mABjnwEosDDqmzw8aTAYECb3avDuGY2rmcjgh4H6RE w08d63j1T4d5J9wlm4TGtW/VHgbUFkATEdH3Acl/EjFiyqTiX7p8kU6Reu5enIkogA93xoQh Rmy7ZiST/5LN+ZkaOdyjIw0L+5KalslN9SKt809YxgJ6kPo657LNTFPiFvFA46/SEWcBYrzq Xk0wEW0gBRWf+BqN0qRhU0/EQ+QfRdLLFg2xtUePwlheYLXxfyDLrdCCOLWYpkzbjCZHLS4u 69smbvR9S9KBDNzJybxEWrkCDQRcXOzIARAA5IGRWTqaM44IJgBYghZg2fGj0Am7KWPhE7V7 T/EEe7vVSUEFqHtlHzI4ZK6Q0AZ9uAEjE8IJIQ7KoTjzNqAtabP0vp3s0szgtJlsZ+8vGKlQ my7fvzSrdoQL0Xn7CEwJYFXJ1EMUcYIQeoHG1cUAaXx73k9BFbjwjnUeMrqlV/ZovQlg7duW nESfQ7HZu5NrtYyY3jPMUouxiO9WQPh+IHxZbt1absF2VcvRAymD32RxGvMPbw6ChMRD/p9O 4PH7M5rXaxr78NXQX9E48vrI00f1cYb9NSN1HnSV8cW3jKObVjdBk6jPQwrMvdpgdQhUB9aZ HS/9mC9mmAgiXKyCpzXe7FPB6QznSfn4GIaC/luy1e6SLUkJhRK/niB+gq+Mfxg2zXNuDUTI cMGmpDCp3kgUoorkaltk8RW09io95BkXrGhcDNuSGZfAParBc7RXyYpbIcax8St7tEAd2oFh 4seYOPUlzuhGrPpqR/91wrFc4E1260GKauSr4UhMJv6tygBwyC0mmBMKi+ZXw6ZdZxA5fg7y 35P3TILjznCXXTDgRHq9A3NknKRMcgFacX6eIhANkMFo6oJVjuEgy1dvu1wFfDq7c+i8GAHu L4pYzyXYu6PporlNNU0xSwdVgzM/uuK0lt+UxCimgC+YR3IezgDcbfudb7h9dGIwL+bbPL0A EQEAAYkCNgQYAQgAIBYhBNnuy6u48FpLrRsJhe8Qz9da75mcBQJcXOzIAhsMAAoJEO8Qz9da 75mcXZ4P/1YXgWDZek7mhzrf6uaQzMxa92P89HeWz4PlgB/32symeEFAV04WazzBZffI8AYY rGA1Xmu/2VaB9+FOODyKhUWBc2UL0NRWBk6POwboyTdKlclmpixaN9zLcBt0YLejoRfN1B/5 aQf9/lUDZMnAiCyz0FgeqEMUshldmwWC35RqnjrCbbuk2vIqSH6BLDIXU6jQrLHE1DF0ai41 wLtQFAFXPhn45n0ZwYhVs4Z32z4sjXrIvgBgCaXa4HM+L1Klne0KiNM8ReFTTpTE0SgyDOSZ O3MOa2n77i6JbVtsbiFYnNeP3J9S/l3jevGpZEtNQOKrIm1MW8jGuHWtsDeMkT/mCcSodlkt PxIo+mMK9GpGvG2hW80LiohqNfUbNwAmr3blOYY4URPXPRnEnPs4pmTmL5owjw2dkg145i9I D42Tq+XZ6YtWt3SGzGbAYow6XwTwZ5NFAzV9UQuCGrDw4KWan6O6Z+VIYWsn0UMZlu1Obxna aocofkaUCbISK26kImuD1aA8juSHC18Qv1xUage6/UakbSxyDtACqt6hOVFKX3IA59ApdNRT +2x3iCmlvF9MJsGgFq6IpqL+Fk7iWV8Kjbz0wQOId6N9+JdQh3LrLaS7a1PowUm1z9DK5/O0 Yg+gpDnEOOFI7WM5u7a7FSM2Z/LXGVwel/0eWvLk9tN6 Message-ID: <83481e30-392b-a105-85c0-8c9d75ed0c61@gmail.com> Date: Tue, 23 Jun 2020 14:37:20 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0 SeaMonkey/2.53.2 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 In-Reply-To: <27641ea5-ecc3-4e7c-a799-139680335d6b@www.fastmail.com> Content-Type: multipart/alternative; boundary="------------CDC3BDDB5A54C7AC6CF00E44" X-Archives-Salt: f922ff8a-3f48-4914-ab5a-b2b069fe849e X-Archives-Hash: d9d63c5d9f685c0fa21fbf785c39cba9 This is a multi-part message in MIME format. --------------CDC3BDDB5A54C7AC6CF00E44 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sid Spry wrote: > > On Tue, Jun 23, 2020, at 12:26 PM, Dale wrote: >> SMART can't predict the future so it can only monitor for the things >> it can see. If say a spindle bearing is about to lock up suddenly, >> SMART most likely can't detect that since it is a hardware failure that >> can't really be predicted. We may be able to hear a strange sound if we >> lucky but if it happens suddenly, it may not even do that. While SMART >> can't predict all points of failures, it can detect a lot of them. Even >> if the two drives I had failed with no warning from SMART, I'd still >> run it and monitor it. Using SMART can warn you in certain situations. >> If a person doesn't run SMART, they will miss those warnings. >> >> SMART isn't perfect but it is better than not having it all. >> > Well, in theory SMART should be able to predict hardware failures like > that through N-th order effects that percolate up to read and write > statistics. In practice it seems to be guessing badly. > > The danger of SMART is that rate of false negatives is so high (IME) that > you might erroneously think a drive is not going to fail and putting off a > backup. A good backup policy should mitigate this, but you still might plan > around drive lifetime SMART predicts before realizing they are or can be > bad predictions. > > Thing is, drives fail at some point.  SMART, while not perfect, can detect problems that indicate a failure.  Let's say for example a person because of the false positives decides not to run SMART at all.  What are they going to use to figure out if a drive is working like it should?  Is a drive having problems reading, writing or noticing corrupt data that is a sign of a problem?  Is it about to fail somehow?  It's not like there is really any other tool that does this.  if one doesn't use the tool, they can have a failure that they could have been warned about and not lose data or very little data.  If a person runs it tho, at least they have something that can detect some failures and prevent data loss.  It's safer to run SMART and get notified when it detects a problem than it is to not run it and have no way of knowing there is a problem at all.  Sure, backups are something everyone should do for important data.  I have backups here, multiple backups of some data.  Still, I run SMART and pay attention to the emails it sends when something is not right.  In the past, it has saved me from data loss.  I'm sure there is many false positives out there but ignoring the real positives isn't a good solution either.  By all means, if one wants to just wing it and hope for the best, disable SMART and take the risk.  At some point, a drive will fail and without SMART, likely with no warning at all, not even a false one.  ;-) Dale :-)  :-)  --------------CDC3BDDB5A54C7AC6CF00E44 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 8bit
Sid Spry wrote:

On Tue, Jun 23, 2020, at 12:26 PM, Dale wrote:

 SMART can't predict the future so it can only monitor for the things 
it can see. If say a spindle bearing is about to lock up suddenly, 
SMART most likely can't detect that since it is a hardware failure that 
can't really be predicted. We may be able to hear a strange sound if we 
lucky but if it happens suddenly, it may not even do that. While SMART 
can't predict all points of failures, it can detect a lot of them. Even 
if the two drives I had failed with no warning from SMART, I'd still 
run it and monitor it. Using SMART can warn you in certain situations. 
If a person doesn't run SMART, they will miss those warnings. 

 SMART isn't perfect but it is better than not having it all. 


Well, in theory SMART should be able to predict hardware failures like
that through N-th order effects that percolate up to read and write
statistics. In practice it seems to be guessing badly.

The danger of SMART is that rate of false negatives is so high (IME) that
you might erroneously think a drive is not going to fail and putting off a
backup. A good backup policy should mitigate this, but you still might plan
around drive lifetime SMART predicts before realizing they are or can be
bad predictions.


Thing is, drives fail at some point.  SMART, while not perfect, can detect problems that indicate a failure.  Let's say for example a person because of the false positives decides not to run SMART at all.  What are they going to use to figure out if a drive is working like it should?  Is a drive having problems reading, writing or noticing corrupt data that is a sign of a problem?  Is it about to fail somehow?  It's not like there is really any other tool that does this.  if one doesn't use the tool, they can have a failure that they could have been warned about and not lose data or very little data.  If a person runs it tho, at least they have something that can detect some failures and prevent data loss. 

It's safer to run SMART and get notified when it detects a problem than it is to not run it and have no way of knowing there is a problem at all.  Sure, backups are something everyone should do for important data.  I have backups here, multiple backups of some data.  Still, I run SMART and pay attention to the emails it sends when something is not right.  In the past, it has saved me from data loss. 

I'm sure there is many false positives out there but ignoring the real positives isn't a good solution either.  By all means, if one wants to just wing it and hope for the best, disable SMART and take the risk.  At some point, a drive will fail and without SMART, likely with no warning at all, not even a false one.  ;-)

Dale

:-)  :-) 
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