[CentOS] Kernel crash

Thu Oct 12 21:12:41 UTC 2017
m.roth at 5-cent.us <m.roth at 5-cent.us>

Diego Farias wrote:
> Hi everyone,
> I updated the kernel from 3.10.0-514.16.1.el7.x86_64
> to  3.10.0-693.2.2.el7.x86_64 . While I was following these steps
> https://wiki.centos.org/HowTos/Laptops/Wireless/Broadcom (I knew that I
> needed to compile again everything) in order to activate WIFI, the laptop
> crashed doing
> # depmod -a
> # modprobe wl
> Noting that I replaced (naively) # depmod $(uname -r) from the guide
> (stupid mistake, I use tcsh and the command above didn't work; that's why
> the replacement).
> After the crash, I had to manually shutdown the laptop. Then, I booted the
> same kernel and it went to 'emergency mode'; as I don't have the root
> password (second stupid mistake; I'm superuser but I don't remember the
> root password/nor I can change it -I don't know-) I couldn't do a thing.
> Then, I booted the previous kernel, 3.10.0-514.16.1.el7.x86_64 (which
> works
> fine), removed 3.10.0-693.2.2.el7.x86_64 (yum remove), and reinstalling it
> from zero. Oddly,
> when I boot with the new kernel, the laptop crashes before login; the caps
> lock light tilts and nothing happens. I've done this several times and the
> same.
> I know I can use the older kernels to work, but I really want to fix this
> if possible.
> Thanks in advance.

Congrats. It's nice to know other folks have the same problem I do, except
mine was on a honkin' Dell R730 server with lots of cores and memory.

Btw, folks, the normal update installs teh "with debugging" as an option;
I *assuem* that it has crash kernel enabled. However, /etc/kdump.conf is
default configured to dump to /var/crash, which has nothing at all in it.
Also - I believe I mentioned it, it kernel panics *just* as it tries to
switch root.

Diego, can you tell if you're getting a kernel panic?