[RHEL5.2] Multipath is using non-preferred "ghost" device paths instead of preferred "ready" ones on IBM DS4700 storage array

Issue

• multipathing is causing the server to move path(s) to non-preferred controller(s) after boot

• multipath -v4 -ll shows the issue:

"Good" device (note "active" group with "ready" device):
mpath8 (3600a0b80004203aa0000076d47c17696) dm-8 IBM,1814      FAStT
[size=70G][features=1 queue_if_no_path][hwhandler=1 rdac]
\_ round-robin 0 [prio=-1][active]
\_ 0:0:0:8 sdi 8:128 [active][ready]
\_ round-robin 0 [prio=-1][enabled]
\_ 0:0:1:8 sds 65:32 [active][ghost]

"Bad" device (note "active" group with "ghost" device - upon use causes reported issue):

mpath9 (3600a0b800042043c000007de47c17691) dm-9 IBM,1814      FAStT
[size=70G][features=1 queue_if_no_path][hwhandler=1 rdac]
\_ round-robin 0 [prio=-1][active]
\_ 0:0:1:9 sdt 65:48 [active][ghost]
\_ round-robin 0 [prio=-1][enabled]
\_ 0:0:0:9 sdj 8:144 [active][ready]