Red Hat DEVICE-MAPPER MULTIPATH 5.2 Configuration And Administration Manual page 37

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