Re: Why would a recreation cause a different number of blocks??

[Jeff Wiegley <jeffw@csun.edu>]

I'll look into this. I kind of thought about that sort
of thing and I went and installed ubuntu 12.04 which I
thought was what I started this all with but I might
have done it earlier than 12.04 and I might have used
gentoo.

are the mdadm defaults specific to mdadm version or
would ubuntu and gentoo have specified different
defaults in something like an /etc/defaults/ourmdadm.cfg?

If it's mdadm then could I just grab old copies of mdadm
sources and compile them one version after the other and
try each one?

Thanks,

- Jeff

On 4/24/2014 8:34 PM, Mikael Abrahamsson wrote:
> On Thu, 24 Apr 2014, Jeff Wiegley wrote:
>
>> Why did my block counts change? The disk partitions weren't touched
>> or changed at any point. Shouldn't I have gotten the same size?
>
> Defaults in mdadm has changed over time, so data offsets might be
> different. In order to get the exact same data offset you need to use the
> same mdadm version as was originally used, or at least know the values it
> used and use mdadm 3.3 that allows you to specify these data at creation
> time,
>
>> The created device isn't work. There is suppose to be luks encrypted
>> volume there but luksOpen reports there is no luks header. (and there
>> use to be). Would the odd change in size indicate total corruption?
>
> No, the change in size indicates that data offsets are not the same so
> your beginning of volume is now in the wrong place.
>