[CentOS] Panic on boot with 7.3 kernels when decrypting hard drive

[Christopher St. Louis]

>> You need to capture the actual panic, or else it's just guessing.
>> Boot without the rhgb quiet kernel args.
>> 
>> Also check it's not just something silly like running out os space
>> on /boot causing incomplete/corrupt initramfs.
>> 
>> jh

Thanks for the advice. Df reports that /boot has 80% free space right
now; I would assume that's enough but I don't know. I need to remove a
few of the old kernels I've got taking up space. There are a few
initramfs-*kdump.img files that have appeared that I assume might be
helpful in tracking down the problems?

I changed the boot arguments (and also added the args to
automatically reboot following a panic, which fixes one of my
problems), and I'm definitely getting kernel panics. Both 4.4.39-1 and
4.9.0-1 end up with pretty much the same issue: "Kernel panic - not
syncing: Fatal exception in interrupt." I know the details of the panic
can/should be kept in a log somewhere, but that's where my limited
experience fails me--I see references to Xorg.0.log and boot.log
online, but those seem to only keep the details of the most recent
boot. I used the not-so-high-tech method of taking a photo of my
laptop's screen output before it restarted, and it seems like the panic
details for both kernels started with a "BUG: unable to handle kernel
NULL pointer dereference at 0000000000000008" and followed shortly by
an "Oops: 0000 [#1] SMP."

Beyond that, the behavior seems to be somewhat inconsistent--the first
time I booted the 4.9 kernel without the quiet rhgb args it seemed to
hang on something related to ipv6 setup without actually getting into a
panic, but I foolishly didn't capture any of the other details. The
pre-7.3 4.4.36-1 kernel that had been working just fine now seems to
fail in a panic every other boot, and I'm currently working from within
the latest 3.10.0-514 kernel that came with 7.3, which had previously
failed to boot in a panic as well.

This is somewhat embarassing because I was feeling pretty confident that
I had pretty much gotten the hang of regular Linux use, but now it
feels like I somehow caused some major problems when I updated to 7.3
(though I didn't do anything beyond "yum update.") If I were back on
Windows, this would be the part where I backup my files and start from
a fresh install, since that was usually the least painless way to fix
major system problems. Is there a possibility that this is fixable, or
would that be a good strategy to employ here? Or does this suggest
something more serious, like a hardware issue?

My apologies for dragging beginner's issues here into a mailing list
for an enterprise OS; CentOS just works so nicely, decently responsive
with low resource usage and was (up until now) completely stable on my
aging X301.

Thanks again.