System won't boot after loss of power

[Polytropon]

On Sat, 25 Apr 2015 11:54:37 -0400, Robert Fitzpatrick wrote:
> I can use Live CD and make changes to the /etc/fstab to use the slices 
> of one pair of drives and chroot to the existing system without gmirror 
> and read all the data from all the partitions. This works for all drives 
> updating fstab for each pair of drives.
> 
> No matter how I update the fstab file, I just get a blinking cursor 
> without reaching the FreeBSD boot manager at all. How can I diagnose 
> further or restore the boot process?

The boot manager has nothing to do with /etc/fstab,
which "happens much later". If you encounter a problem
at an early booting stage, the reason is to be searched
for there.

Maybe... is the boot manager damaged or absent? Check
the partition properties with gpart. In worst case,
re-install the boot manager (with gpart or bsdlabel,
depending on how you have partitioned your drives).
Are you sure the system is trying to boot from the
correct drive? Can you interrupt at the boot prompt
or the loader prompt, or don't you even reach those?
If you can, verify that the correct root device is
being configured.

Also, just in case, check if there's something strage
regarding the boot order in your BIOS / UEFI.

Everything else at this poing is just WAG... :-(


-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...