On Mon, 11 Feb 2013, Daniel Sanabria wrote:

Thanks a million Guys !!! I re-created the RAID and fsck it and it's 
mounting fine now. The array is my /home partition and I can't see any 
significant losses. But I'm still not sure what happened, I mean what 
consideration should I take next time I upgrade?

First of all: --create --assume-clean is a huge big enormous hammer. It 
shouldn't be used unless absolutely necessary, when all other options are 
exhausted.

I am not aware of any gotchas when upgrading, I have done it numerous 
times, even moved array drives between machines, and it's worked well so 
far. From your information there isn't really any way to tell what 
happened.

So best way before next upgrade is to save mdadm --examine and hope it 
works properly (it should). If it doesn't, please send an email to the 
list with as much information as possible (mdadm --examine, dmesg etc) and 
see where that leads before using the big hammer.

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se