Setup Guide

path_grouping_policy group_by_prio
path_checker tur
detect_prio yes
failback immediate
no_path_retry 3
rr_min_io_rq 1
fast_io_fail_tmo 15
max_sectors_kb 1024 //only for RHEL 6.9 (or later 6.x versions) and RHEL 7.4 (or later 7.x
versions)
}//other devices}
}
Parameter Description Value
vendor Specifies the vendor name DellEMC
product The below configuration applies only to PowerStore volumes. PowerStore
path_selector Sends the next group of I/Os to the path with the least number of
outstanding I/O requests
queue-length 0
path_grouping_policy Specifies the default path grouping policy to apply to PowerStore
volumes
● Paths are grouped by priorities assigned by the cluster.
● A higher priority (50) is set as Active/Optimized. Lower
priority (10) is set as Active/Non-Optimized.
group_by_prio
path_checker Specifies TEST UNIT READY as the default method used to
determine the state of the paths.
tur
detect_prio If set to yes, multipath will try to detect whether the device
supports ALUA. If so, the device will automatically use the alua
prioritizer. Otherwise, the prioritizer will be selected as usual.
Default value is no.
yes
failback Manages the path group failback. Immediate refers to
immediate failback to the highest priority path group that contains
active paths.
Immediate
no_path_retry Specifies the number of times the system should attempt to use a
failed path before disabling queuing.
3
rr_min_io_rq Specifies the number of I/O requests to route to a path before
switching to the next path in the same path group, using request-
based device-mapper-multipath. This setting should be used on
systems running current kernels. On systems running kernels older
than 2.6.31, use rr_min_io. Default value is 1.
1
fast_io_fail_tmo Specifies the number of seconds the scsi layer will wait after a
problem has been detected on a FC remote port before failing I/O
to devices on that remote port. This value should be smaller than
dev_loss_tmo. Setting this parameter to off will disable the
timeout.
15
max_sectors_kb Applies to Red Hat Enterprise Linux Release 6.9 (or later 6.x
versions) and Red Hat Enterprise Linux Release 7.4 (or later 7.x
versions).
Sets the max_sectors_kb device queue parameter to the
specified value on all underlying paths of a multipath device
before the multipath device is first activated. When a multipath
device is created, the device inherits the max_sectors_kb
value from the path devices. Manually raising this value for the
1024
36 Host Configuration for Linux