All docs wrongly stated that as valid. It is not, mainly
because path checker selection happens before assigning the
path to a multipath.
Thanks to Matthew Kent for pointing this out.
# path_grouping_policy multibus
#
# #
-# # name : path_checker
-# # scope : multipathd
-# # desc : path checking alorithm to use to check path state
-# # values : readsector0|tur|emc_clariion|hp_sw|directio
-# # default : directio
-# #
-# # path_checker directio
-#
-# #
# # name : path_selector
# # desc : the path selector algorithm to use for this mpath
# # these algo are offered by the kernel mpath target
# wwid 3600508b4000156d700012000000b0000
# alias yellow
# path_grouping_policy multibus
-# path_checker directio
# path_selector "round-robin 0"
# failback manual
# rr_weight priorities
.TP 18
.B path_grouping_policy
.TP
-.B path_checker
-.TP
.B path_selector
.TP
.B failback