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<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif">\ufeff</span><o:p></o:p></p>
<p class="MsoNormal"><span style="font-family:"Calibri",sans-serif">\ufeff</span></p>
<p class="MsoNormal">Hi,</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We\u2019re doing another file system migration. We\u2019d like users to have read-only access to the existing filesystem during and then for a while after the final sync.</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">The 2 mechanisms we\u2019re looking at are setting the MDTs read-only using \u201clctl set_param mdt.*.readonly=1\u201d and remounting the filesystem on all the clients using \u201cmount -o remount,ro\u201d.</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">My impression is that in the case of setting the MDTs read-only, files already opened in write mode will still be writable. For remounting, if files are opened in write mode the remount will fail and complain that the file system is busy.
Our current plan is to do the remounting of all clients because it\u2019s easier to see if some user has some file open in write mode.</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is there a way to make the file system read-only that\u2019s minimally disruptive to users but doesn\u2019t have the potential problem of having to chase down every process writing to the filesystem?</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,</p>
<p class="MsoNormal">Gian-Carlo DeFazio</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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