Short tip: Please reserve memory by passing 'crashkernel=X@Y' parameter to the kernel

calendar Apr 29, 2015 · 1 min read · kurztipp  ·
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While configuring kdump on a system I recently stumbled upon the following error:

1Please reserve memory by passing "crashkernel=X@Y" parameter to the kernel

However, the parameter crashkernel was mentioned in the GRUB configuration file and kernel commandline:

1$ grep crashkernel /proc/cmdline
2ro root=/dev/mapper/vg_system-lv_root ... crashkernel=auto ... rhgb quiet

I saw that this setting works for other systems.

The reason for this issue was that the affected system had less than 2 GB of memory. In accordance with the Red Hat Enterprise Linux documentation the parameter value auto is ineffective in this scenario. To fix this, it is necessary to manually set a value. In my case I set the default value 128 MB:

1# vi /boot/grub/menu.lst
2...
3ro root=/dev/mapper/vg_system-lv_root ... crashkernel=128M ... rhgb quiet
4...
5
6ESC ZZ

After rebooting the system I was able to configure kdump.

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