Re: endianness of Linux kernel RAID

On Monday August 8, blinux_adm@yahoo.com wrote:

I have a PowerPC based NAS device that was damaged by
a recent a brownout.  The drives in the array are
fine, but the device's firmware was corrupted.  My
first attempt to assemble the array on my x86 system
failed due to the endian differences.  After applying
this patch, the mdadm examine command worked
perfectly.  As of yet, I have not attempted to update
the superblocks.  I would like to leave the original
superblocks intact so that I can reinstall the drives
in my NAS device when it is repaired.  Is it possible
to assemble the array without overwriting the
superblocks?

Not really....  The kernel reads the superblocks to find out the
details of the array.  If it cannot read them, it won't assemble the
array.

Depending on the type of array, you could --build the array instead.
This allows for arrays that deliberately don't have superblocks.
It should work for raid0, might work for linear, could work for raid1,
but no for anything else.

If you want to try it, send me the --examine output. and I'll suggest
a command.

NeilBrown