Bug#321008: multipathd ignores prio_callout

[Stephen Frost]

Package: multipath-tools
Version: 0.4.2.4-2
Severity: normal

Greetings,

  For some reason that I havn't been able to identify as yet, multipathd
  appears to just outright ignore the prio_callout setting.  Looking in
  /var/cache/multipathd, it's empty, so perhaps that's the problem.
  There's no errors in the logs though.  multipath directly works fine
  though.

  ie:

  default_prio_callout    "/sbin/path_prio.sh %d"

  
[This is correct...]
sauron:/etc/rcS.d# multipath -v2 -S

create: sarndata (3600a0b800016057c0000176c42e92517)
[size=892 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [first]
  \_ 1:0:0:0 sdb  8:16    [ready ]
\_ round-robin 0
  \_ 1:0:1:0 sdd  8:48    [ready ]

create: sarnwal (3600a0b800016029a0000088a42e92bb8)
[size=108 GB][features="0"][hwhandler="0"]
\_ round-robin 0
  \_ 1:0:0:1 sdc  8:32    [ready ]
\_ round-robin 0 [first]
  \_ 1:0:1:1 sde  8:64    [ready ]

[This is incorrect...]
sauron:/etc/rcS.d# /etc/init.d/multipath-tools start
Starting multipath daemon: multipathd.

sauron:/etc/rcS.d# multipath -v2 -S -l
sarnwal (3600a0b800016029a0000088a42e92bb8)
[size=108 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [enabled][first]
  \_ 1:0:0:1 sdc  8:32    [ready ][active]
\_ round-robin 0 [enabled]
  \_ 1:0:1:1 sde  8:64    [ready ][active]

sarndata (3600a0b800016057c0000176c42e92517)
[size=892 GB][features="0"][hwhandler="0"]
\_ round-robin 0 [active][first]
  \_ 1:0:0:0 sdb  8:16    [ready ][active]
\_ round-robin 0 [enabled]
  \_ 1:0:1:0 sdd  8:48    [ready ][active]

As you may notice, in the 'correct' setup, sdb and sde are marked as
'first', and my SAN picks up that the correct controllers are being 
used for those LUs.  In the 'incorrect' setup, sdc and sdb are marked as
'first', which ends up having both LUs accessed via the same controller,
a less than optimal solution.  Additionally, these really shouldn't ever
be different, aiui, they should both be making use of path_prio.sh,
which I've configured to return the correct values (as can be seen by
the fact that multipath picks up the correct solution).

	Thanks,

		Stephen