mdmpd fails to start.

[Alexandre Oliva]

On Aug  5, 2004, akonstam at trinity.edu wrote:

> Mdmpd fails to start on our Fedora Core 2 systems with the error:
>  Kernel md module does not support events

>  We are currently running Kernel 2.6.7-1.494.2.2
>  but the ame thing was happening in earlier kernels.

>  What does this daemon do, and under what circumstances would we need
>  it?

It's equivalent to mdmonitor (that quite likely starts as well, and
successfully), with the difference that mdmonitor doesn't rely on a
line looking like `Events: ##' in /proc/mdstat.  The RHEL kernel has
such a line, that enables a slightly more efficient raid event
monitor, since it can immediately tell that nothing changed if the
event count matches what it got last it looked at the file.

IMHO it's a mistake to ship mdmpd in FC, and a double mistake to ship
it enabled by default, especially given the noisy failure mode.  The
init script should probably integrate mdmpd and mdmonitor into a
single init script that tests for Events: support in the kernel and
starts the most efficient md monitor or so.

-- 
Alexandre Oliva             http://www.ic.unicamp.br/~oliva/
Red Hat Compiler Engineer   aoliva@{redhat.com, gcc.gnu.org}
Free Software Evangelist  oliva@{lsd.ic.unicamp.br, gnu.org}