On 2018.12.06 15:58, Dale wrote:
[snip...]
My concern is this tho. I have my old CPU still installed and
everything is compiled based on that. So, I'm stable with the old
CPU. However, when I shutdown, take out the old CPU and install the
new one, I'm concerned it may not boot at all because of the change
or may boot but be very unstable. I recall years ago being able to
set up the flags in such a way that it can run on virtually any CPU
but it's been a long time ago and I don't know if it is needed or
not. My hope was, someone did a very similar upgrade and can say for
sure if it works or if I need to do things before changing the CPUs
to make sure I can boot and be stable. If I can just get a stable
console, I can do a emerge -e world and get the OS inline with the
CPU. I'm just concerned whether I will have that or not.
[snip...]
I just don't want to swap CPUs only to find out I've got to swap back
because my system won't boot at all. Heck, it may even fail to load
the kernel itself for all I know.
I once made the mistake of getting a whole new (used...) PC and just
moved the HDD from the old one to the new, without thinking about any
of this. Of course it wouldn't boot at all, because I was switching
from an AMD to an Intel CPU and had set all flags accordingly in the
old box. In your case, as long as you include any flags necessary for
the new CPU, and remove any flags for features the new CPU does not
have, you should be good. (I know that sounds simple, but does ignore
how you find that info.) Given your two CPUs are relatively close
(unless I misread something) there should be little if anything
critical to change.
However, if you have a live DVD, (or on USB stick) that will always
boot, and you can then do a chroot and reset flags and start
recompiling whatever might fail. I actually think the kernel IS the
likely failure if any, but once that boots, you should be good to
recompile whatever fails. (Yes, toolchain stuff might be an issue, but
again, just boot back to the live DVD.) You may need to reboot a few
times, but you won't need to swap the old CPU back in.
Jack
