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<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Hello Thomas,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">I wanted to let you know that the maximum size of the LDISKFS backend is continuously being increased.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">The 16 TB limit was set a long time ago, and the current limit for LDISKFS partition size is now 1024TB.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">However, for development or non-production purposes, there is an option called "force_over_512tb" that allows us to ignore this limitation.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Please note that there is still a limit of 4G inodes per partition, but Lustre FS can scale by using more targets for data and metadata.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Best regards,
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US">Artem Blagodarenko<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><b><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">From:
</span></b><span style="font-size:12.0pt;font-family:"Aptos",sans-serif;color:black">lustre-discuss <lustre-discuss-bounces@lists.lustre.org> on behalf of Thomas Roth via lustre-discuss <lustre-discuss@lists.lustre.org><br>
<b>Date: </b>Friday, 2 February 2024 at 13:35<br>
<b>To: </b>lustre-discuss@lists.lustre.org <lustre-discuss@lists.lustre.org><br>
<b>Subject: </b>[lustre-discuss] ldiskfs / mdt size limits<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">Hi all,<br>
<br>
confused about size limits:<br>
<br>
I distinctly remember trying to format a ~19 TB disk / LV for use as an MDT, with ldiskfs, and failing to do so: the max size for the underlying ext4 is 16 TB.<br>
Knew that, had ignoed that, but not a problem back then - just adapted the logical volume's size.<br>
<br>
Now I have a 24T disk, and neither mkfs.lustre nor Lustre itself have show any issues with it.<br>
'df -h' does show the 24T, 'df -ih' shows the expected 4G of inodes.<br>
I suppose this MDS has a lot of space for directories and stuff, or for DOM.<br>
But why does it work in the first place? ldiskfs extends beyond all limits these days?<br>
<br>
Regards,<br>
Thomas<br>
<br>
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