Neil Brown wrote:

On Thursday October 18, davidsen@tmr.com wrote:
  

quoted

Unless there's a substantial benefit from using the 1.0 format, you 
might want to go with something which works. 
    

I am every grateful to the many people who do not just find work
arounds, but report problems and persist until they get fixed.

Obviously everyone should choose the path that suits them best, but
I'd rather we didn't discourage people who are working to get a bug
fixed. 
  

Giving them a way to get working and copying you directly seems to be a 
reasonable compromise between ignoring the problem and leaving the 
original poster to think software raid is neither reliable nor supported.

I have never seen any guidance on when 1.0 or 1.2 format is better than 
1.1, perhaps that can go on the documentation queue.

quoted

                                              I would suggest using 
--bitmap-chunk, but the man page claims it doesn't apply to internal 
bitmaps. It also claims the bitmap size is chosen automatically to best 
use available space, but "doesn't work" seems an exception to "best 
use." ;-)
    

In this case, it does work, and it is best use.  It just appears that
the 'available space' is not truly available - read error.
  

It's not always clear without dmesg if read error is hardware :-( I 
certainly assumed it was config or software in nature.

-- 
bill davidsen [off-list ref]
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979