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<p>Mark,</p>
<p>Sorry, you don't get off that easy :P. You have to choose, and
not choosing means you choose what follows.<br>
</p>
<p>I'll offer one more option: we can use 10TB drives instead of
8TB. Probably slightly longer rebuild times, but actually higher
streaming bandwidth. Cost will go up, maybe a few $K. I think we
can find a way to squeeze that out of the system.<br>
</p>
<p>Default choice if no one else votes is now this: new /work server
is procured with 44 drives, 10 TB HGST He10 enterprise drives (top
rated, new big brother to our He8 drives). If Physics is poor, we
can defer buying them the read cache SSD to compensate for the
higher price of 10TB (Graham, can you swing an extra $3K?).<br>
</p>
<p> 21 drives for ENP, 21 for LQCD, 2 hot spares in a 44
drive enclosure (SSDs in hosts)<br>
</p>
<p> ENP and LQCD each get total quota (enforced) of 108 TB</p>
<p> GlueX, CLAS-12 each get 44 TB, A and C get 10 TB
(enforced)<br>
</p>
<p>CLAS-12 says they can live within this, and C believes they are
already there. GlueX and A will need to figure out what can be
moved into /volatile.<br>
</p>
<p>If requested, we can give you modest lifetime "pin" for /volatile
so some large data files that should not go to tape can have
longer lifetimes in Lustre /volatile than they can today.</p>
<p>Next year, for about $10K we can add a second cascaded JBOD next
year with one more RAID stripe for ENP. We'll also need to spend
$25K to replace the Lustre storage that ages out in FY18 (or
suffer the reduction).<br>
</p>
<p>regards, <br>
</p>
<p>Chip<br>
</p>
<br>
<div class="moz-cite-prefix">On 6/8/17 9:40 AM, Mark Ito wrote:<br>
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<p>That was just an observation. I would not interpret it as a
vote for anything... <span class="moz-smiley-s1"><span>:-)</span></span><br>
</p>
<br>
<div class="moz-cite-prefix">On 06/08/2017 09:33 AM, Chip Watson
wrote:<br>
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<p>I'll take this as a vote by GlueX to have more work and
reduce cache.</p>
<p>Do A,B,C concur?<br>
</p>
<br>
<div class="moz-cite-prefix">On 6/8/17 9:28 AM, Mark Ito wrote:<br>
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<p>In my previous estimate, of the cache portion, 278 TB, only
105 TB of that is pinned. The unpinned part is presumeably
old files that should be gone, but have not been deleted
since there happens to be no demand for the space. If we use
105 TB as our cache usage then re-doing your estimate gives
555 TB, which means in 9 months we will have 270 TB of
unused space. Which would mean that we have room to increase
our usage without buying anything!<br>
</p>
<br>
<div class="moz-cite-prefix">On 06/07/2017 05:54 PM, Chip
Watson wrote:<br>
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<p>Mark,</p>
<p>I still need you to answer the question of how to further
reduce usage and how to configure. Your usage as you
report it is about 370 TB. Assuming that Hall B needs the
same within 9 months, and that A+C need half as much, then
that leads to a total of 925TB which is more than Physics
owns, by 100 TB (NOT CURRENT USAGE, JUST PROJECTION BASED
ON GLUEX USAGE).<br>
</p>
<p>There is also the question of how to split the storage
budget. In budget, you can have new half a JBOD: 21 disks
configured as 3 RAID z2 stripes of 5+2 disks, 8TB, thus
120 raw data, 108 in a file system, and 86 TB at 80% --
for all of GlueX, CLAS-12, A and C. If GlueX is 40% of
the total, that makes 35TB, and you are still high by 70%.</p>
<p>The other low cost option is to re-purpose a 2016 Lustre
node so that /work is twice this size (one full JBOD), and
GlueX can use 70TB as /work. But then you must reduce
/cache + /volatile by a comparable amount since we have to
pull a node out of production. And this still isn't free
since we'll need a total of 4 RAID cards instead of 2 to
provide correct performance, and we'll need to add SSD's
to the mix.<br>
</p>
<p>So, in the absence of money (which clearly seems to be
the case), do you choose (a) reduce your use of work by
1.7x, or (b) reduce your use of cache + volatile by 25%.
There is no middle case.<br>
</p>
<p>thanks,</p>
<p>Chip<br>
</p>
<br>
<div class="moz-cite-prefix">On 6/7/17 5:30 PM, Mark Ito
wrote:<br>
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<p>Summarizing Hall D work disk usage (/work/halld only):</p>
<p>o using du, today 2017-06-06, 59 TB<br>
</p>
<p>o from our disk-management database, a couple of days
ago, 2017-06-04, 86 TB</p>
<p>I also know that one of our students got rid of about
20 TB of unneeded files yesterday. That accounts for
part of the drop.<br>
</p>
<p>We produce a <a moz-do-not-send="true"
href="https://halldweb.jlab.org/disk_management/work_report.html">report
from that database</a> that is updated every few days.</p>
<p>From the SciComp pages, Hall D is using 287 TB on cache
and 21 TB on volatile.</p>
<p>My view is that this level of work disk usage is more
or less as expected, consistent with our previous
estimates, and not particularly abusive. That having
been said, I am sure there is a lot that can be cleaned
up. But as Ole pointed out, disk usage grows naturally
and we were not aware that this was a problem. I seem to
recall that we agreed to respond to emails that would be
sent when we reached 90% of too much, no? Was the email
sent out?<br>
</p>
<p>One mystery: when I ask Lustre what we are using I get:</p>
<pre>ifarm1402:marki:marki> lfs quota -gh halld /lustre</pre>
<pre>Disk quotas for group halld (gid 267):</pre>
<pre> Filesystem used quota limit grace files quota limit grace</pre>
<pre> /lustre 290T 470T 500T - 15106047 0 0 -</pre>
which is less than cache + volatile, not to mention work.
I thought that to a good approximation this 290 TB should
be the sum of all three. What am I missing?<br>
<br>
<div class="moz-cite-prefix">On 05/31/2017 10:35 AM, Chip
Watson wrote:<br>
</div>
<blockquote type="cite"
cite="mid:53cbb78f-3f2c-5fe0-c925-96e90b733bf1@jlab.org">All,
<br>
<br>
As I have started on the procurement of the new /work
file server, I have discovered that Physics' use of
/work has grown unrestrained over the last year or two.
<br>
<br>
"Unrestrained" because there is no way under Lustre to
restrain it except via a very unfriendly Lustre quota
system. As we leave some quota headroom to accommodate
large swings in usage for each hall for cache and
volatile, then /work continues to grow. <br>
<br>
Total /work has now reached 260 TB, several times larger
than I was anticipating. This constitutes more than 25%
of Physics' share of Lustre, compared to LQCD which uses
less than 5% of its disk space on the un-managed /work.
<br>
<br>
It would cost Physics an extra $25K (total $35K - $40K)
to treat the 260 TB as a requirement. <br>
<br>
There are 3 paths forward: <br>
<br>
(1) Physics cuts its use of /work by a factor of 4-5. <br>
(2) Physics increases funding to $40K <br>
(3) We pull a server out of Lustre, decreasing Physics'
share of the system, and use that as half of the new
active-active pair, beefing it up with SSDs and perhaps
additional memory; this would actually shrink Physics
near term costs, but puts higher pressure on the file
system for the farm <br>
<br>
The decision is clearly Physics', but I do need a VERY
FAST response to this question, as I need to move
quickly now for LQCD's needs. <br>
<br>
Hall D + GlueX, 96 TB <br>
CLAS + CLAS12, 98 TB <br>
Hall C, 35 TB <br>
Hall A <unknown, still scanning> <br>
<br>
Email, call (x7101), or drop by today 1:30-3:00 p.m. for
discussion. <br>
<br>
thanks, <br>
Chip <br>
<br>
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<pre class="moz-signature" cols="72">--
Mark Ito, <a class="moz-txt-link-abbreviated" href="mailto:marki@jlab.org" moz-do-not-send="true">marki@jlab.org</a>, (757)269-5295
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<pre class="moz-signature" cols="72">--
Mark Ito, <a class="moz-txt-link-abbreviated" href="mailto:marki@jlab.org" moz-do-not-send="true">marki@jlab.org</a>, (757)269-5295
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<pre class="moz-signature" cols="72">--
Mark Ito, <a class="moz-txt-link-abbreviated" href="mailto:marki@jlab.org" moz-do-not-send="true">marki@jlab.org</a>, (757)269-5295
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