Re: How to recover after md crash during reshape?

[Andras Tantos <andras@tantosonline.com>]

Phil,

On 10/28/2015 9:42 AM, Phil Turmel wrote:
> If you stop the array cleanly and then manually re-assemble with 
> --update=metadata, you might get around it. (Specify all of the 
> devices explicitly to ensure you don't get burned by v0.90's problems 
> with last partitions.) You definitely don't want to stay on v0.90, but 
> you may need to for now to get out of trouble. Phil 

It seems that my mdadm doesn't have an --update=metadata option, which 
if I understand it right means I have to re-create the array with the 
no-bitmap option. How dangerous is that? Is it possible that things get 
overwritten during the re-create process in the data portion of the array?

I've read that GRUB (which is my bootloader) didn't support v1.0 
superblocks for a while. It seems that 0.99 version of GRUB (which is 
what I have) has it, but how to make certain? I don't want to render my 
system un-bootable...

Can you expand a little bit on the problems of v0.90 superblocks and why 
upgrading is advantageous? What I've read about the differences (lifted 
limit of number of devices/array and 2TB per device limit) don't really 
apply to my case.

Thanks,
Andras