On Mon, Mar 29, 2010 at 07:31:43AM +0100, Jools Wills wrote:

i notice in the mdadm git head this has been changed to

       mapnames(VAR_RUN "/map"),
       mapnames("/var/run/mdadm.map"),
       mapnames(ALT_RUN "/" ALT_MAPFILE)

and the description has been almost corrected (albeit some typos) to

*   /var/run/mdadm/map  /var/run/mdadm.map  /lib/initrw/madam/map

however, these paths are still not helpful for the ubuntu initramfs that
doesn't have these locations - and there is not an obvious fall back
location.

i tought ubuntu had /lib/init/rw, being debian based, or is it only the
mdadm subdire under that one missing? current git should create the
latter.

Also changing the ALT_RUN location will also change where it stores the
PID for the monitor daemon, which is called much later once root is
mounted, so even if ALT_RUN is set to /dev/ so the map file could be
created. it wouldn't be the ideal location for the PID.

not exactly, mdmon is spawned by mdadm in case an array with external
metadata is assembled (imsm or ddf)

Since things tend to fail if it cant make the mapfile how about it
tries /dev/ as a final location for the file (or another location that
is likely to exist) if the others fail? Another option that would work,
is to create a folder such as /var/run if it is missing, or allow the
map file path to be passed as a parameter, so the location guesswork
could be overridden by the caller.

since ALT_RUN and VAR_RUN are settable at compile time, i believe every
distro can chose a suitable path.

Also, some error reporting that the map file couldn't be created would
be most useful, instead of the "/dev/md0 is in use" error.

yes, this would be needed

My final thought is, that to make this bug report, I had to come and
sign up here on this list, and then hope that the mdadm maintainer will
read it. The mdadm software really needs a bugtracker, or better
instructions on the site as to how to go about reporting issues.

What's wrong about a mailing list?

L.

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