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<p class="MsoNormal">Hello All, <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Currently I am investigating the bootup failures which I see on our 0penBmc based boards when the rw-fs is full.
<o:p></o:p></p>
<p class="MsoNormal">The rw-fs can become full because of many reasons. One example being too frequent bmc dump creation which are stored in rw-fs.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have allocated 16MB for the read-write fs and part of the init sequence there is overlay file system which is being mounted as the root-fs which combines the ro-fs and the rw-fs.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<pre style="text-indent:.5in;background:white"><span style="color:black"><a href="https://grok.openbmc.org/s?defs=mount&project=openbmc"><span style="color:#2030A2;text-decoration:none">mount</span></a> -t <a href="https://grok.openbmc.org/s?defs=overlay&project=openbmc"><span style="color:#2030A2;text-decoration:none">overlay</span></a> -o <a href="https://grok.openbmc.org/s?defs=lowerdir&project=openbmc"><span style="color:#2030A2;text-decoration:none">lowerdir</span></a>=<a href="https://grok.openbmc.org/s?defs=%24rodir&project=openbmc"><span style="color:#2030A2;text-decoration:none">$rodir</span></a>,<a href="https://grok.openbmc.org/s?defs=upperdir&project=openbmc"><span style="color:#2030A2;text-decoration:none">upperdir</span></a>=<a href="https://grok.openbmc.org/s?defs=%24upper&project=openbmc"><span style="color:#2030A2;text-decoration:none">$upper</span></a>,<a href="https://grok.openbmc.org/s?defs=workdir&project=openbmc"><span style="color:#2030A2;text-decoration:none">workdir</span></a>=<a href="https://grok.openbmc.org/s?defs=%24work&project=openbmc"><span style="color:#2030A2;text-decoration:none">$work</span></a> <a href="https://grok.openbmc.org/s?defs=cow&project=openbmc"><span style="color:#2030A2;text-decoration:none">cow</span></a> /<a href="https://grok.openbmc.org/s?defs=root&project=openbmc"><span style="color:#2030A2;text-decoration:none">root</span></a><o:p></o:p></span></pre>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Above ‘mount overlay’ command fails with the below error when the upperdir which the rw-fs is full.
<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:.5in"><o:p> </o:p></p>
<pre style="text-indent:.5in;background:white"><span class="MsoHyperlink"><span style="color:#2030A2;text-decoration:none">chroot: can't execute '/bin/sh': No such file or directory<o:p></o:p></span></span></pre>
<pre style="text-indent:.5in;background:white"><span class="MsoHyperlink"><span style="color:#2030A2;text-decoration:none">Unable to confirm /sbin/init is an executable non-empty file<o:p></o:p></span></span></pre>
<pre style="text-indent:.5in;background:white"><span class="MsoHyperlink"><span style="color:#2030A2;text-decoration:none">in merged file system mounted at /root.<o:p></o:p></span></span></pre>
<pre style="text-indent:.5in;background:white"><span class="MsoHyperlink"><span style="color:#2030A2;text-decoration:none">Change Root test failed!<o:p></o:p></span></span></pre>
<pre style="text-indent:.5in;background:white"><span class="MsoHyperlink"><span style="color:#2030A2;text-decoration:none">Fatal error, triggering kernel panic!<o:p></o:p></span></span></pre>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Basically, when the ‘overlayfs’ fails there is no rootfs mounted on the /. So, I am thinking the subsequent init sequence fails.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I am very much interested in knowing if anyone has any thoughts on solving this issue or has encountered and already found some existing solutions.
<o:p></o:p></p>
<p class="MsoNormal">One solution which is in my mind is to capture the failure of mount overlay command and do a self-clean-up procedure on the rw-fs with a white-list policy.
<o:p></o:p></p>
<p class="MsoNormal">Thanks for any kind input. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regards,<o:p></o:p></p>
<p class="MsoNormal">Rohit PAI <o:p></o:p></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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