install_keyword("polling_interval", &polling_interval_handler, &snprint_def_polling_interval);
install_keyword("udev_dir", &udev_dir_handler, &snprint_def_udev_dir);
install_keyword("multipath_dir", &multipath_dir_handler, &snprint_def_multipath_dir);
- install_keyword("selector", &def_selector_handler, &snprint_def_selector);
+ install_keyword("path_selector", &def_selector_handler, &snprint_def_selector);
install_keyword("path_grouping_policy", &def_pgpolicy_handler, &snprint_def_path_grouping_policy);
install_keyword("getuid_callout", &def_getuid_callout_handler, &snprint_def_getuid_callout);
install_keyword("prio", &def_prio_handler, &snprint_def_prio);
# polling_interval 10
#
# #
-# # name : selector
+# # name : path_selector
# # scope : multipath & multipathd
# # desc : the default path selector algorithm to use
# # these algorithms are offered by the kernel multipath target
# # values : "round-robin 0"
# # default : "round-robin 0"
# #
-# selector "round-robin 0"
+# path_selector "round-robin 0"
#
# #
# # name : path_grouping_policy
#defaults {
# udev_dir /dev
# polling_interval 5
-# selector "round-robin 0"
+# path_selector "round-robin 0"
# path_grouping_policy failover
# getuid_callout "/lib/udev/scsi_id --whitelisted --device=/dev/%n"
# prio const
#defaults {
# udev_dir /dev
# polling_interval 10
-# selector "round-robin 0"
+# path_selector "round-robin 0"
# path_grouping_policy multibus
# getuid_callout "/lib/udev/scsi_id --whitelisted --device=/dev/%n"
# prio const
levels are between 0 and 6; default is
.I 2
.TP
-.B selector
+.B path_selector
The default path selector algorithm to use; they are offered by the
-kernel multipath target. The only currently implemented is
-.I "round-robin 0"
+kernel multipath target. There are three selector algorithms.
+.RS
+.TP 12
+.B "round-robin 0"
+Loop through every path in the path group, sending the same amount of IO to
+each.
+.TP
+.B "queue-length 0"
+Send the next bunch of IO down the path with the least amount of outstanding IO.
+.TP
+.B "service-time 0"
+Choose the path for the next bunch of IO based on the amount of outstanding IO
+to the path and its relative throughput.
+.RE
.TP
.B path_grouping_policy
The default path grouping policy to apply to unspecified