On Sat, Jun 28, 2014 at 01:37:44PM -0500, Bruno Wolff III wrote:
If netconsole is built as a module, you can't use it to capture
before the module gets loaded. Rebuilding Fedora srpms (to get Fedora
patches) takes pretty long, which makes testing slow.
I have something particular I am testing now (probably a nouveau related
crash) that crashes for netconsole gets loaded (though I tried to add it to
the initramfs to get it loaded fairly early). I am not sure if it will be
early enough even if it is built in. I won't know until sometime tomorrow.
But if it does get loaded early enough to handle video card related stuff,
it seems like it be worth having built into debug kernels.
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Even building it all (netconsole+dependent network drivers) isn't typically
enough, since you also need to bring the network interface up and assign an ip
address to it, which happens fairly late in the boot cycle. If you have a crash
that occurs so early that you're thinking about doing this, a RAC device with
serial console support is usually a better bet.
That said, it would be nice if dracut had a module that allowed you to include
netconsole so that you could set it up before you did a switch_root.