On 1/28/26 02:32, D. R. Evans wrote:
...
It turns out that the BIOS on the computer doesn't seem to provide any
way to boot from USB. The best I can do, as far as I can tell, is to
create a live DVD and boot from that.
So I have booted from a live CD (which is very slow, but does
eventually succeed), and made sure that the only hard drive in the
machine is the RAID device that I am trying to fix.
That is strange, how old is your hardware? When you mentioned 2013 I was
thinking 4th gen Intel CPU and Haswell-era hardware, which should
support USB-boot.
...
_Exactly_ what chroot command do you want me to type at this point?
I am sorry I wasn't more clear. What I meant to say is that you have to
get the output data from the OS you trying to rescue, not the host OS.
In other words, after you change root "/etc/fstab" will point to fstab
on the RAID disk you trying to rescue, and if you don't it will point to
fstab of the host system on non-RAID disk.
So "to chroot" means the same sequence of commands as before, but
without grub-install:
mkdir /tmp/RFS
mount /dev/md126 /tmp/RFS #Mount root filesystem
mount --bind /dev /tmp/RFS/dev #Mount bind real /dev to populate
chroot-ed /dev
mount --bind /proc /tmp/RFS/proc #Mount bind real /proc to
populate chroot-ed /proc
mount --bind /sys /tmp/RFS/sys #Mount bind real /systo populate
chroot-ed /sys
chroot /tmp/RFS /usr/bin/bash #Change root into directory /tmp/RFS
Now you can issue those commands and get output:
cat /etc/fstab
cat /boot/grub/grub.cfg | grep -iE -- "--set=root|root=|insmod"