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<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="moz-cite-prefix">El 22/07/18 a las 04:02, Jonathan
Engwall escribió:<br>
</div>
<blockquote type="cite"
cite="mid:CAP=T6ZPCUF6aSB7H-W-QsE7qMPDH67Rp9HAmromVBO3qrn--xQ@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<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"
moz-do-not-send="true">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"
target="_blank" rel="noreferrer" moz-do-not-send="true">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" target="_blank"
moz-do-not-send="true">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>
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<div
class="m_-1779906929510931293m_292805406280346994HOEnZb">
<div
class="m_-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"
target="_blank" moz-do-not-send="true">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_-1779906929510931293m_292805406280346994m_-7803825350429064010h5"><br>
> On 22 Jul 2018, at 05:42,
Jonathan Engwall <<a
href="mailto:engwalljonathanthereal@gmail.com"
rel="noreferrer noreferrer"
target="_blank"
moz-do-not-send="true">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>
>
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