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<div class="moz-cite-prefix">On 11/18/23 04:17, Stephen Worthington
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:8e1hlip29i5sq4il2709vkku3mhq02pub9@4ax.com">
<pre class="moz-quote-pre" wrap="">On Fri, 17 Nov 2023 22:06:02 -0600, you wrote:
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<pre class="moz-quote-pre" wrap="">Thanks for your concern. I thought a lot before choosing this path.
Yes, I did my calculations. My SSDs have 600TBW and at 30GB per day, I
am looking at 54 years of life (600*1000/30/365 ~ 54). I also have
smartd doing its thing. It will report when SSDs start using their spare
blocks. At about $60/TB (for 54 years of claimed life), I feel it is a
fair game.
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<pre class="moz-quote-pre" wrap="">
That certainly sounds good. But do check the smartctl -a output - my
new 1 Tbyte SSD in my main MythTV box is only 214 days old, and is
currently showing 16.1 TBytes written without me doing any recording
to it (75 Gbytes per day). It says it is 1% used, so it is still
going to last a long time, even at that rate.
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<pre class="moz-quote-pre" wrap="">So far, in my mythtv usage (10+ years), I have had 10+ spinning disks
die. I have still my very first SSD (256G SATA) and several others as I
have no use for them with newer/larger SSDs replacing the old ones.
So, I am looking to try them out to see if TBW values really happen.
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<pre class="moz-quote-pre" wrap="">
Over the last 10 years I think I will have had 10+ hard drives die
also, but only 2 of them prematurely. The others had been running for
a long time, over their expected lifetime. I now am buying enterprise
class drives (20+ Tbytes) with 5 year warranties, but they have not
been around for more than 5 years yet. I do have two ancient
enterprise class 3 Tbyte HGST drives that I swapped out because they
were too small after 9-10 years 24/7. I put one of them into my
mother's MythTV box running 24/7 again a couple of months later. It
is currently showing 105553 power on hours (12 years) and is showing
no problems at all. They were not cheap when I bought them, but they
do show that enterprise class drives can last a very long time.
</pre>
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<pre class="moz-quote-pre" wrap="">Suppose I am wrong and my SSDs show wear, it is a single mythtv-setup
change that will get back to trashing spinning disks.
</pre>
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<pre class="moz-quote-pre" wrap="">
Yes, very easy to do. I really like how storage groups work.
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<pre class="moz-quote-pre" wrap="">When I record and watch at the same time, the amount of seek is very
noticeable (especially with RAIDs) and I prefer the random access
capabilities of SSDs.
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<pre class="moz-quote-pre" wrap="">
With my enterprise class drives, I can have them recording 2
programmes at once and playing back at the same time with no problems.
>From the specifications, I would think three recordings at once would
be fine too, but I never get to that as I have 7 recording drives. I
can certainly hear them seeking, but it does not sound over the top at
all. But I can also do 2 recordings plus playback from my old (very
quiet) WD Green 4 Tbyte drives, which have much lower specifications.
They are currently showing 81029 and 77591 power on hours (9.2 and 8.9
years). So even cheap drives can last well if you get lucky and they
were over designed.
I am wondering if RAID 1 is the problem somehow. If the data was
being written to the first drive and then read back again to be copied
to the second drive, that might cause what you are getting. But that
would be a really bad way of doing RAID 1 when you can just write to
both drives at once from the same buffers.
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<pre class="moz-quote-pre" wrap="">Regards
Ramesh
</pre>
</blockquote>
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</blockquote>
What I meant by noticeable is that I can hear the disks and see the
activity lights and disks hunting. No issues with actual myth
performance. I simply think that the seek should be avoided, if
possible. It just annoys me and makes me wonder if the wear-and-tear
is eventually going to get my disks. <br>
<br>
Yes, my 2TB HGST (enterprise) is running past its 10th year. BTW, I
bought this refurbished from an unknown vendor on ebay. Clearly they
used to make good enterprise disks. Now everything is really
spinning rust. I only buy enterprise spinners and that too across
brands and batches so that I really get average life from them.
However, I am not confident on spinners anymore and they are also
very big these days making any operation risky of in process
failures. I will learn in the next 10 years if SSDs are just a
different kind of rust or they actually live long like other
electronic circuits. Early experiments on SSDs do indicate that they
could be the latter. <br>
<br>
Regards<br>
Ramesh<br>
<br>
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