Kernel Panic booting cdrom
dhuffman at storix.com
Sat Apr 21 07:05:11 EST 2007
I think I determined why I received a kernel panic and the numa=off
argument fixed the problem. When we boot from cdrom we specify maxcpus=1
as a kernel argument. A system with numa enabled fails. I plan on
adding numa=off whenever I use maxcpus=1, but I wonder if you could
answer a question for me.
I originally was told that in the case where I am booting a basic system
into an initrd instead of in normal mode, I should use maxcpus=1 because
there may be power and cooling daemons that are not running and try to
limit the system resources by limiting the number of cpus. Does this
sound right? I can successfully boot a cdrom without the maxcpus flag on
an SMP system but maybe it is typically not a good idea?
I can prevent the kernel panics by removing maxcpus=1 and not adding
numa=off. I am a little more informed about numa (now), but I am fuzzy
as to all the implications with allowing more cpus for cdrom install
media. The maxcpus=1 argument was something we added to our install boot
media years ago and few here remember why it was such a great idea. The
power/resource management was the only thing we could come up with.
Nathan Lynch wrote:
> David Huffman wrote:
>> Thank you very much for the info. This worked to get the system booted
>> from cdrom. However, in normal mode, the numa=off argument is not in the
>> yaboo.conf file. Any idea why it works without it in normal mode, but
>> requires numa=off when using the same kernel and booting from cdrom?
> No, that doesn't make sense to me. If you'd like to dig deeper into
> it, diff -u the output of dmesg from both boots. (and please copy the
> list next time, thanks :)
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