<div dir="auto">Ariel,<div dir="auto"><span style="font-family:sans-serif;font-size:13.696px">Sorry I cannot share any images. It was crashing through the night. Before I write the new boot I will take a screenshot if possible.</span><br></div></div><br><div class="gmail_quote"><div dir="ltr">On Sun, Jul 22, 2018, 6:52 AM ariel sabiguero yawelak <<a href="mailto:asabigue@fing.edu.uy">asabigue@fing.edu.uy</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
  
    
  
  <div text="#000000" bgcolor="#FFFFFF">
    <p>Cheap drives (I use Crucial, AMD Radeon and Kingston) accept
      3.000 rewrites per memory block. There are a few of interesting
      attributes you can check from SMART. These are from my laptop
      (Crucial_CT960M500SSD1)<br>
    </p>
    <p><br>
    </p>
    <p><tt>ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH
        TYPE      UPDATED  WHEN_FAILED RAW_VALUE</tt><tt><br>
      </tt><tt>  9 Power_On_Hours          0x0032   100   100   000   
        Old_age   Always       -       8611</tt><tt><br>
      </tt><tt> 12 Power_Cycle_Count       0x0032   100   100   000   
        Old_age   Always       -       4800</tt><tt><br>
      </tt><tt>173 Ave_Block-Erase_Count   0x0032   096   096   000   
        Old_age   Always       -       134</tt><tt><br>
      </tt><tt>180 Unused_Reserve_NAND_Blk 0x0033   000   000   000   
        Pre-fail  Always       -       16523</tt><tt><br>
      </tt><tt>202 Percent_Lifetime_Used   0x0031   096   096   000   
        Pre-fail  Offline      -       4</tt><tt><br>
      </tt><tt>206 Write_Error_Rate        0x000e   100   100   000   
        Old_age   Always       -       0</tt><tt><br>
      </tt><tt>210 Success_RAIN_Recov_Cnt  0x0032   100   100   000   
        Old_age   Always       -       0</tt><tt><br>
      </tt><tt>246 Total_Host_Sector_Write 0x0032   100   100   ---   
        Old_age   Always       -       19329755627</tt><tt><br>
      </tt><tt>247 Host_Program_Page_Count 0x0032   100   100   ---   
        Old_age   Always       -       616802682</tt><tt><br>
      </tt><tt>248 Bckgnd_Program_Page_Cnt 0x0032   100   100   ---   
        Old_age   Always       -       3344366909</tt><tt><br>
      </tt></p>
    <p><br>
    </p>
    <p>Attribute 173 states that, on average, each block was erased 134
      times, and states that it is about 4% of the liftime of the drive
      (attribute 202) was used. Check those/similar values on your
      drive. 4% on 8.611hs suggests that I can continue to use the drive
      another 23 more years.<br>
    </p>
    <p>A few things you should consider:</p>
    <ul>
      <li>There is no wear from reading</li>
      <li>You should have as much free space as possible in order to
        level the wearing. If your filesystem is pretty much full, all
        the wear-leveing will occur on those few blocks that are
        released and re-used. If you only have one block left, you will
        kill it in 3000 writes :-)<br>
      </li>
      <li>Your filesystem shouls be aware that it is running on SSD in
        order to mark blocks as free (so the SSD can do it's magic). I
        finally dropped reiserfs for this reason.</li>
      <li>lot more things to consider, but these are the most relevant
        IMHO</li>
      <li>YMMV<br>
      </li>
    </ul>
    <p><br>
    </p>
    <p>Would you like to share your counters? Filesystem? application?<br>
    </p>
    <p>regards</p>
    <p>ariel<br>
    </p>
    <br>
    <div class="m_8889575810078768552moz-cite-prefix">El 22/07/18 a las 04:02, Jonathan
      Engwall escribió:<br>
    </div>
    <blockquote type="cite">
      
      <div dir="auto">Does 345 power_on_hours seem like "old age"
        <div dir="auto">Not happy. Thanks for the CEPH tip.</div>
      </div>
      <br>
      <div class="gmail_quote">
        <div dir="ltr">On Sat, Jul 21, 2018, 11:30 PM Jonathan Engwall
          <<a href="mailto:engwalljonathanthereal@gmail.com" target="_blank" rel="noreferrer">engwalljonathanthereal@gmail.com</a>>
          wrote:<br>
        </div>
        <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
          <div dir="auto">I built up a couple r610 dells with the idea
            that they would boot from ssd through a usb external drive.
            The cheap external drives might be the real culprits. I have
            to think about that.
            <div dir="auto">The latest drive to fail was a Kingston and
              I think it was new.</div>
            <div dir="auto">There is a write limit on some ssds?</div>
            <div dir="auto">Lately I have been building trying to
              crosscompile the cray xmp simulator. It has thousands of
              targets. But earlier this week afterI installed
              openvswitch was when the trouble began.</div>
            <div dir="auto">Jonathan Engwall</div>
          </div>
          <br>
          <div class="gmail_quote">
            <div dir="ltr">On Sat, Jul 21, 2018, 10:44 PM John Hearns
              via Beowulf <<a href="mailto:beowulf@beowulf.org" rel="noreferrer noreferrer" target="_blank">beowulf@beowulf.org</a>>
              wrote:<br>
            </div>
            <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
              <div dir="ltr">
                <div><span style="text-align:left;color:rgb(34,34,34);text-transform:none;text-indent:0px;letter-spacing:normal;font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant:normal;font-weight:400;text-decoration:none;word-spacing:0px;display:inline;white-space:normal;direction:ltr;float:none;background-color:transparent">I
                    forgot the main purpose of the Internet. My bad.</span><span style="text-align:left;color:rgb(34,34,34);text-transform:none;text-indent:0px;letter-spacing:normal;font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant:normal;font-weight:400;text-decoration:none;word-spacing:0px;display:inline;white-space:normal;direction:ltr;float:none;background-color:transparent"><br>
                  </span></div>
                <div><span style="text-align:left;color:rgb(34,34,34);text-transform:none;text-indent:0px;letter-spacing:normal;font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant:normal;font-weight:400;text-decoration:none;word-spacing:0px;display:inline;white-space:normal;direction:ltr;float:none;background-color:transparent"><span style="font:400 13.33px arial,sans-serif;text-align:left;color:rgb(34,34,34);text-transform:none;text-indent:0px;letter-spacing:normal;text-decoration:none;word-spacing:0px;display:inline;white-space:normal;font-size-adjust:none;font-stretch:100%;float:none;background-color:transparent">></span><span style="text-align:left;color:rgb(34,34,34);text-transform:none;text-indent:0px;letter-spacing:normal;font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant:normal;font-weight:400;text-decoration:none;word-spacing:0px;display:inline;white-space:normal;direction:ltr;float:none;background-color:transparent">You
                      don't say for which purpose the SSDs are being
                      used.</span></span></div>
                <div><span style="text-align:left;color:rgb(34,34,34);text-transform:none;text-indent:0px;letter-spacing:normal;font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant:normal;font-weight:400;text-decoration:none;word-spacing:0px;display:inline;white-space:normal;direction:ltr;float:none;background-color:transparent"><span style="text-align:left;color:rgb(34,34,34);text-transform:none;text-indent:0px;letter-spacing:normal;font-family:arial,sans-serif;font-size:12.8px;font-style:normal;font-variant:normal;font-weight:400;text-decoration:none;word-spacing:0px;display:inline;white-space:normal;direction:ltr;float:none;background-color:transparent">Storing
                      cat pics?</span></span></div>
              </div>
              <div class="gmail_extra"><br>
                <div class="gmail_quote">On 22 July 2018 at 07:41, John
                  Hearns <span dir="ltr"><<a href="mailto:hearnsj@googlemail.com" rel="noreferrer noreferrer noreferrer" target="_blank">hearnsj@googlemail.com</a>></span>
                  wrote:<br>
                  <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
                    <div dir="ltr">
                      <div>You don't say for which purpose the SSDs are
                        being used.</div>
                      <div>In your laptop?</div>
                      <div>As system disks in HPC compute nodes?</div>
                      <div>Journalling drives in a parallel filesystem?</div>
                      <div>Data storage drives in a parallel filesystem?</div>
                      <div><br>
                      </div>
                      <div>Over on the CEPH mailing list there are
                        regular topics on choice of SSDs. I would advise
                        going over there and asking the same question.</div>
                      <div><br>
                      </div>
                      <div>Also you don't say how they are failing.</div>
                      <div>Are these consumer grade drives or data
                        centre grade drives?</div>
                      <div>Consumer drives have much, much lower 'drive
                        writes per day'</div>
                      <div><br>
                      </div>
                      <div>Two jobs ago I would have said the go-to data
                        centre drives were Intel.</div>
                      <div><br>
                      </div>
                      <div>Also one comment specific to HPC. I found
                        that SSD drives dont 'get sick' like spinning
                        drives,</div>
                      <div>ie you dont see syslog messages about blocks
                        failing to be read/written. They just fail.</div>
                      <div>Also two jobs ago I though that SMART checks
                        were not picking up failing SSDs.</div>
                      <div>I believe that you can monitor them if you
                        choose the correct counters. Anyone?</div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                      <div><br>
                      </div>
                    </div>
                    <div class="m_8889575810078768552m_-1779906929510931293m_292805406280346994HOEnZb">
                      <div class="m_8889575810078768552m_-1779906929510931293m_292805406280346994h5">
                        <div class="gmail_extra"><br>
                          <div class="gmail_quote">On 22 July 2018 at
                            07:32, Jonathan Aquilina <span dir="ltr"><<a href="mailto:jaquilina@eagleeyet.net" rel="noreferrer noreferrer noreferrer" target="_blank">jaquilina@eagleeyet.net</a>></span>
                            wrote:<br>
                            <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">What Ones are
                              you currently getting?<br>
                              <br>
                              Sent from my iPhone<br>
                              <div>
                                <div class="m_8889575810078768552m_-1779906929510931293m_292805406280346994m_-7803825350429064010h5"><br>
                                  > On 22 Jul 2018, at 05:42,
                                  Jonathan Engwall <<a href="mailto:engwalljonathanthereal@gmail.com" rel="noreferrer noreferrer noreferrer" target="_blank">engwalljonathanthereal@gmail.com</a>>
                                  wrote:<br>
                                  > <br>
                                  > I am not happy with the SSDs I am
                                  using. I am buying another sad every
                                  couple weeks.<br>
                                  > Fast sure, but my productivity
                                  right now is zero.<br>
                                  > Are there any recommendations on
                                  reliable ssd brands?<br>
                                  > Jonathan Engwall<br>
                                </div>
                              </div>
                              >
                              _______________________________________________<br>
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                            </blockquote>
                          </div>
                          <br>
                        </div>
                      </div>
                    </div>
                  </blockquote>
                </div>
                <br>
              </div>
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            </blockquote>
          </div>
        </blockquote>
      </div>
      <br>
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      <br>
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</pre>
    </blockquote>
    <br>
  </div>

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</blockquote></div>