prefered way to update mdadm/mdadm.conf

prefered way to update mdadm/mdadm.conf

[Timothy D. Lenz]

There seems to be 2 ways to update mdadm.conf. One puts a little more info in and both create duplicate info that msut be removed.
Which is the better way:

mdadm --examine --scan >> /etc/mdadm/mdadm.conf
mdadm --detail --scan >> /etc/mdadm/mdadm.conf

Also, is there a way to check if mdadm "damenised" at boot for sending email alerts? mdstat only list the arrays, not any kind of
monitoring level.

Re: prefered way to update mdadm/mdadm.conf

[Federico]

I'm using mdadm --examine --scan >> /etc/mdadm/mdadm.conf because with
--detail mdadm report also the  metadata=  which produces warning
during the the boot ("warning: metadata=00.90 not recognize" or
something like that).

Re: prefered way to update mdadm/mdadm.conf

[Neil Brown]

On Friday April 17, tlenz@vorgon.com wrote:
> There seems to be 2 ways to update mdadm.conf. One puts a little more info in and both create duplicate info that msut be removed.
> Which is the better way:
> 
> mdadm --examine --scan >> /etc/mdadm/mdadm.conf
> mdadm --detail --scan >> /etc/mdadm/mdadm.conf

The best way to create mdadm.conf is with an editor.
Understand the syntax of the file, understand what you want mdadm to
do to assemble/monitor arrays.  And create a file that suits.
The two commands are useful for pre-populating the file but should not
be considered a 'final' answer.
They are useful in different contexts.

> 
> Also, is there a way to check if mdadm "damenised" at boot for
> sending email alerts? mdstat only list the arrays, not any kind of 
> monitoring level.

"ps axgu  | grep mdadm"

is a good way.

NeilBrown

Re: prefered way to update mdadm/mdadm.conf

[Luca Berra]

On Fri, Apr 17, 2009 at 02:16:22PM -0700, Timothy D. Lenz wrote:
>There seems to be 2 ways to update mdadm.conf. One puts a little more info in and both create duplicate info that msut be removed.
>Which is the better way:
>
>mdadm --examine --scan >> /etc/mdadm/mdadm.conf
>mdadm --detail --scan >> /etc/mdadm/mdadm.conf

the former will check physical devices for md superblock, and read
information from the found sb.
the latter will query active array for information

I use mdadm -Esc partition | grep ARRAY >> /etc/mdadm/mdadm.conf
to inventory all array whether they are active or not.

I still would suggest checking the content of mdadm.conf after.

L.

-- 
Luca Berra -- bluca@comedia.it
         Communication Media & Services S.r.l.
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