Kdump Helper

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Kdump is a reliable kernel crash-dumping mechanism that captures crash dumps for troubleshooting issues like kernel crashes, hangs, and reboots. Setting up Kdump usually requires a series of steps and configurations. The Kdump Helper app is designed to simplify the process and reduce the effort required to set up Kdump on your machines.

Input a minimum amount of information and this app will generate an all-in-one script for you to set up Kdump to dump data in memory into a dump file called a vmcore. It has two modes: guided mode and manual mode . If you just want to input minimum information and use default or recommended parameters whenever possible, simply use the guided mode (the default mode), which then presents you a few steps with clear instructions to help you choose or input a proper parameter. If you have a very good understanding of Kdump and want to control as many options as possible, the manual mode will be your choice. It allows you to adjust all parameters.

Once you click the "Generate" button, the app will generate a script for you to set up Kdump based on the information you provided. Just run it on your server, and after it finishes, your Kdump service will be ready to capture crash dumps.

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BZ 990302 is assigned state, talking about how crashkernel=auto does not work for large physical memory machines. Does this tool take that into account? Thanks, Rick Beldin (rick.beldin@hp.com)

Yes, on RHEL6.x we set the crashkernel by the follow rule.

RHEL6 crashkernel compute


    ram size    crashkernel parameter   ram / crashkernel factor
    >0GB              128MB                         15
    >2GB              256MB                         23
    >6GB              512MB                         15
    >8GB              768MB                         31

We use crashkernel=auto for RHEL7 only, because starting with RHEL7 kernels crashkernel=auto should be used. The kernel will automatically reserve an appropriate amount of memory for the kdump kernel.



The new UI looks awesome, we are using it as well.

In the future will this also include the ability to panic on different NMI?

what's the most recent version of kexec-tools for RHEL6.5

You should not modify /etc/sysctl.conf directly to add or change configurations. Instead you can make custom sysctl configuration files in /etc/sysctl.d/ since RHEL 5. This is the preferable way to configure sysctl.

we have a server with 16 CPU, 125 GB memory, running 5.11, the server has about 500 file systems on it, in the kdump helper script I do not see the offset and crashkernel values for memory more than 32 GB.

any recommendations ?

Thank you!

Hi Ravi,
Thank you for contacting us.
For RAM size greater than 24G:
Try crashkernel memory 768M and RAM/crashkernel offset of 32, which looks like 768M@32M.
If you get an Out-Of-Memory error message, then try with increasing the crashkernel parameter to 896M
More details, please read this solution:

Best regards,
Yunfeng Zhao

Hi ,

We have a RAM size of 384GB on RHEL6.7.What shoukld be the memory reservation for this amount of RAM?



When using option 2, mem_total seems to not be initialized in the generated script updateGrub.sh which generates bash errors like : line 19 '[' -le 2 ']'
unary operator expected. Thanks Homi FARIS (homi.faris@hpe.com)

Hi Homi, Thank you for reporting the issue. We have already fixed it. Thanks.

Best regards, Yunfeng Zhao

The man kdump.conf specifies the "net" option is deprecated by "nfs" for nfs dumps.

nfs <nfs mount> | nfs4 <nfs mount> | net <nfs mount>
Will  mount  fs and copy /proc/vmcore to <mnt>/<path>/%HOST-%DATE/, supports DNS. Note that a fqdn should be used as the server name in the mount point. By default, NFSv3 is used, nfs4 will use NFSv4. "net" is deprecated by "nfs"

The kdump helper script put the "net" option instead "nfs". Customer ask me if it is a fully supported configuration ?

Thanks you!

Felipe Aranda G.

Hi Felipe,

Thanks for reporting this issue. we will fix it.

Dong Zhao