Re: Debian kernel stanza after aptitude kernel upgrade

[Neil Brown <neilb@suse.de>]

On Tue, 28 Sep 2010 12:11:35 +0100
Tim Small <tim@seoss.co.uk> wrote:

> On 21/09/10 21:29, Neil Brown wrote:
> >> I think you need to stick the output of
> >>
> >> mdadm --examine --scan
> >>
> >> into /etc/mdadm/mdadm.conf
> >>      
> > It is generally better to use
> >      mdadm --detail --scan
> >
> > for generating mdadm.conf as it is more likely to get the device names
> > right.  And when doing this by hand, always review the output to make sure it
> > looks right.
> >    
> 
> 
> Thanks for that Neil - Debian (and thus Ubuntu) currently uses the 
> output of "mdadm --examine --scan --config=partitions" when 
> autogenerating the mdadm.conf output.  Should this be considered a bug?  
> If so, could you give a bit of detail, and I'll open a bug for the 
> script....
> 
> Thanks,
> 
> Tim.
> 

It all depends on what you want to do.

If you want a config file which described the current configuration, then
"--detail --scan" is definitely the thing to use.
If you want a config file that records what is on the devices currently
attached to the machine, then "--examine --scan" is what you want.

Any use of "--examine --scan" is probably better left to the auto-assembly
stuff in mdadm (mdadm -As).  So Debian should probably be using --detail
--scan.  However without a statement of the exactly purpose and context, one
cannot be certain.

NeilBrown