[gentoo-user] Computer keeps crashing during boot, need dmesg

[Andrew Lowe]

Hi all,
	I'm having all sorts of trouble getting a new computer to boot. I have
two NVME thingies in it with one containing Win10 and the other,
eventually, Gentoo. I use Refind to control the booting with the machine
using UEFI.

	The graphical front end to Refind boots fine and allows me to in turn
boot Windows. It also spots and then allows me to boot a copy of
SysrescueCD that I left plugged in. No joy with Linux. I get up to where
the kernel appears to be doing something with sata and then it crashes.
Now herein lies the problem.

	Is there a way to get dmesg logged to a file so that I can see what's
actually failing? I need to be able to get back into the machine with
SysrescueCD, which is no problem, and then have a look at the dmesg
output to see what's going wrong.

	Does anyone have any idea as to how to do this, or another way of doing
the debugging I'm trying to do? The stuff I've found on the web assumes
that some of the loggers are working and can do stuff, I'm not getting
to the stage where they have started up yet.

	I'm in the process of transferring from a non EFI hard disk setup to
EFI & nvme. The hard disk based system boots with no problems. Assuming
that the hard disk system and the nvme system will give nearly the same
dmesg, looking at the hard disk dmesg, I see that if I go to where I
think is the same posi as the crash on the nvme, is where it attempts to
mount root:

VFS: Mounted root (jfs filesystem) readonly on device 8:19.

If I have managed to do something wrong with respect to this mounting,
would it cause the crash or just complain and freeze?

	Any thoughts on this would be greatly appreciated,

		Andrew