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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Are there any presentation available online that provide diagrams of the directory/file creation process and modifications in terms
of how the blocks/inodes and indirect blocks etc are used. I would guess there are a few different cases that would need to be shown.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">This is the sort of thing that would great in a decent text book on GPFS (doesn’t exist as far as I am aware.)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Cheers,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Greg<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> gpfsug-discuss-bounces@spectrumscale.org [mailto:gpfsug-discuss-bounces@spectrumscale.org]
<b>On Behalf Of </b>Marc A Kaplan<br>
<b>Sent:</b> Thursday, 29 September 2016 1:23 AM<br>
<b>To:</b> gpfsug main discussion list <gpfsug-discuss@spectrumscale.org><br>
<b>Subject:</b> Re: [gpfsug-discuss] Blocksize<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial",sans-serif">OKAY, I'll say it again. inodes are PACKED into a single inode file. So a 4KB inode takes 4KB, REGARDLESS of metadata blocksize. There is no wasted space.</span><br>
<br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif">(Of course if you have metadata replication = 2, then yes, double that. And yes, there overhead for indirect blocks (indices), allocation maps, etc, etc.)</span><br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif"><br>
And your choice is not just 512 or 4096. Maybe 1KB or 2KB is a good choice for your data distribution, to optimize packing of data and/or directories into inodes...</span><br>
<br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif">Hmmm... I don't know why the doc leaves out 2048, perhaps a typo...</span><br>
<br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif">mmcrfs x2K -i 2048</span><br>
<br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif">[root@n2 charts]# mmlsfs x2K -i</span><br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif">flag value description</span><br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif">------------------- ------------------------ -----------------------------------</span><br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif"> -i 2048 Inode size in bytes</span><br>
<br>
<span style="font-size:10.0pt;font-family:"Arial",sans-serif">Works for me!</span><o:p></o:p></p>
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