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<p>Pat,</p>
<p>No, not in general. It just seems that if one is storing data
on an SSD it should be optional to have it not stored in memory (
why store in 2 fast mediums ).</p>
<p>O_DIRECT is not of value as that would apply to all extents,
whether on SSD on HDD. O_DIRECT on Lustre has been problematic
for me in the past, performance wise.<br>
</p>
<p>John<br>
</p>
<div class="moz-cite-prefix">On 5/19/22 13:05, Patrick Farrell
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:DM6PR19MB312958A89DDEDEC0B9E3682AC9D09@DM6PR19MB3129.namprd19.prod.outlook.com">
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<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
No, and I'm not sure I agree with you at first glance.</div>
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<br>
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<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Is this just generally an idea that data stored on SSD should
not be in RAM? If so, there's no mechanism for that other than
using direct I/O.</div>
<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
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<br>
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<div style="font-family: Calibri, Arial, Helvetica, sans-serif;
font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
-Patrick</div>
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<div id="divRplyFwdMsg" dir="ltr"><font style="font-size:11pt"
face="Calibri, sans-serif" color="#000000"><b>From:</b>
lustre-discuss <a class="moz-txt-link-rfc2396E" href="mailto:lustre-discuss-bounces@lists.lustre.org"><lustre-discuss-bounces@lists.lustre.org></a>
on behalf of John Bauer <a class="moz-txt-link-rfc2396E" href="mailto:bauerj@iodoctors.com"><bauerj@iodoctors.com></a><br>
<b>Sent:</b> Thursday, May 19, 2022 12:48 PM<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:lustre-discuss@lists.lustre.org">lustre-discuss@lists.lustre.org</a>
<a class="moz-txt-link-rfc2396E" href="mailto:lustre-discuss@lists.lustre.org"><lustre-discuss@lists.lustre.org></a><br>
<b>Subject:</b> [lustre-discuss] Avoiding system cache when
using ssd pfl extent</font>
<div> </div>
</div>
<div class="BodyFragment"><font size="2"><span
style="font-size:11pt;">
<div class="PlainText">When using PFL, and using an SSD as
the first extent, it seems it would
<br>
be advantageous to not have that extent's file data
consume memory in <br>
the client's system buffers. It would be similar to using
O_DIRECT, but <br>
on a per-extent basis. Is there a mechanism for that
already?<br>
<br>
Thanks,<br>
<br>
John<br>
<br>
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</blockquote>
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