Red Hat DEVICE-MAPPER MULTIPATH 5.2, Configuration And Administration Manual, Page: 37 / 44

Attribute Description
default value is
0
.
rr_min_io
Specifies the number of I/O requests to route to a path before
switching to the next path in the current path group. The
default value is 1000.
rr_weight
If set to
priorities
, then instead of sending
rr_min_io
requests to a path before calling
selector
to choose the next
path, the number of requests to send is determined by
rr_min_io
times the path's priority, as determined by the
prio_callout
program. Currently, there are priority callouts
only for devices that use the
group_by_prio
path grouping
policy, which means that all the paths in a path group will
always have the same priority.
If set to
uniform
, all path weights are equal. The default value
is
uniform
.
no_path_retry
A numeric value for this attribute specifies the number of
times the system should attempt to use a failed path before
disabling queueing.
A value of
fail
indicates immediate failure, without queuing.
A value of
queue
indicates that queuing should not stop until
the path is fixed.
The default value is (null).
Table 4.3. Device Attributes
The following example shows a
device
entry in the multipath configuration file.
# }
# device {
# vendor "COMPAQ "
# product "MSA1000 "
# path_grouping_policy multibus
# path_checker tur
# rr_weight priorities
# }
#}
Configuration File Devices
27