<div dir="ltr"><div>Hi ,</div><div><br></div><div>kdump need 2 kernel primary and secondary. Primary will be panicked, then secondary will do capture coredump. </div><div><br></div><div>In boot loader/ kernel command line specify crashkernel=256MB or more, ensure secondary kernel is small in size so that it can be boot within this memory, oom should not happen. </div><div><br></div><div>Primary config:</div><div>CONFIG_SYSFS=y<br>CONFIG_KEXEC=y<br>CONFIG_DEBUG_INFO=y<br></div><div><br></div><div>Secondary Config:</div><div>CONFIG_PHYSICAL_START=0x100000<br>CONFIG_RELOCATABLE=y<br>CONFIG_CRASH_DUMP=y<br></div><div><br></div><div>load secondary kernel using </div><div>kexec -p  <></div><div><br></div><div>After kernel panic, secondary kernel will be invoked. The secondary kernel should save core from /proc/vmcore  and reboot again. </div><div><br></div><div>Refer kdump kernel docs : <a href="https://www.kernel.org/doc/Documentation/kdump/kdump.txt" class="md-opjjpmhoiojifppkkcdabiobhakljdgm_doc">https://www.kernel.org/doc/Documentation/kdump/kdump.txt</a> </div><div><br></div><div>Thanks,</div><div>Satya  </div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, May 15, 2020 at 11:17 PM 慕冬亮 <<a href="mailto:mudongliangabcd@gmail.com">mudongliangabcd@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="overflow-wrap: break-word;"><br><div><br><blockquote type="cite"><div>On May 15, 2020, at 12:47 PM, Subhashini Rao Beerisetty <<a href="mailto:subhashbeerisetty@gmail.com" target="_blank">subhashbeerisetty@gmail.com</a>> wrote:</div><br><div><div>Hi all,<br><br>In  Kernel, what needs to be configured to get the crash dump?<br>Can someone clarify me with the sequence of steps to get the crash dump..<br><br></div></div></blockquote><div><br></div><div>Some materials for specific Linux distributions(e.g., Redhat, Debian):</div><div><br></div><div><div><a href="https://mudongliang.github.io/2018/07/02/debian-enable-kernel-dump.html" target="_blank">https://mudongliang.github.io/2018/07/02/debian-enable-kernel-dump.html</a></div><div><br></div><div><a href="https://www.bentasker.co.uk/documentation/linux/312-installing-and-configuring-kdump-on-debian-jessie" target="_blank">https://www.bentasker.co.uk/documentation/linux/312-installing-and-configuring-kdump-on-debian-jessie</a></div></div><div><br></div><div><a href="https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/kernel_administration_guide/kernel_crash_dump_guide" target="_blank">https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/kernel_administration_guide/kernel_crash_dump_guide</a></div><div><br></div><div><a href="https://fedoraproject.org/wiki/How_to_use_kdump_to_debug_kernel_crashes" target="_blank">https://fedoraproject.org/wiki/How_to_use_kdump_to_debug_kernel_crashes</a></div><div><br></div><div><br></div><br><blockquote type="cite"><div><div>Thanks,<br><br>_______________________________________________<br>Kernelnewbies mailing list<br><a href="mailto:Kernelnewbies@kernelnewbies.org" target="_blank">Kernelnewbies@kernelnewbies.org</a><br><a href="https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies" target="_blank">https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies</a><br></div></div></blockquote></div><br></div>_______________________________________________<br>
Kernelnewbies mailing list<br>
<a href="mailto:Kernelnewbies@kernelnewbies.org" target="_blank">Kernelnewbies@kernelnewbies.org</a><br>
<a href="https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies" rel="noreferrer" target="_blank">https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies</a><br>
</blockquote></div>