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Required Adapter and Server OS Settings
116 Dell EMC Storage Compatibility Matrix for SC, PS, and FS Series Arrays | DSCM
• node.session.timeo.replacement_timeout = 120
A.2.3.5 SAS volume multipath configuration
SAS connectivity to a Linux system requires specific configuration schema in the /etc/multipath.conf
file. Add the following device section to /etc/multipath.conf used exclusively for SAS-connected Linux
systems. The following example define the configuration parameters for all devices identified by
vendor="COMPELNT" and product="Compellent Vol".
devices {
device {
vendor COMPELNT
product "Compellent Vol"
path_checker tur
prio alua
path_selector "service-time 0"
path_grouping_policy group_by_prio
no_path_retry 24
hardware_handler "1 alua"
failback immediate
rr_weight priorities
}
}
A properly configured SAS volume will return the following multipath -ll output. This SC Series volume is
discovered as a multipath ALUA-capable volume, where each path is capable of I/O. The path represented by
prio=50 (active/optimized path) is used for all active I/O requests. The path represented by prio=1
(standby path) is a highly available, redundant path and is used when the active/optimized path becomes
unavailable.
# multipath -ll
Compelnt_0016 (36000d31000feb3000000000000000016) dm-3 COMPELNT,Compellent Vol
size=100G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio=50 status=active
| `- 1:0:0:1 sdb 8:16 active ready running
`-+- policy='service-time 0' prio=1 status=enabled
`- 1:0:1:1 sdc 8:32 active ready running
Compelnt_001a (36000d31000feb300000000000000001a) dm-4 COMPELNT,Compellent Vol
size=100G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
|-+- policy='service-time 0' prio=50 status=active
| `- 1:0:1:2 sdd 8:48 active ready running
`-+- policy='service-time 0' prio=1 status=enabled
`- 1:0:2:2 sde 8:64 active ready running