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24 Dell EMC SC Series: Red Hat Enterprise Linux Best Practices | CML1031
Start multipathd:
# systemctl start multipathd #For RHEL 7 and newer
# service multipathd start #For RHEL 6 and older
Check the multipathd status:
# systemctl status multipathd #For RHEL 7 and newer
# service multipathd status #For RHEL 6 and older
3.6.4 FC/iSCSI volume multipath configuration
To ease the deployment of native Linux multipath, the software has default settings for an extensive list of
storage models including SC Series storage. The default settings allow the software to work with SC Series
storage right out of the box. However, these settings might not be optimal for all situations and should be
reviewed and modified if necessary.
Create the multipath daemon configuration file on newly installed systems. Copy a basic template from
/usr/share/doc/device-mapper-multipath-<version>/multipath.conf to /etc/multipath.conf as a starting
point. Any settings that are not defined explicitly in the file would assume the default values. Obtain the full list
of these settings using the following command. Specific SC Series settings can be found by searching for
COMPELNT from the output.
# multipathd –k"show config"
To avoid confusion and as a best practice, it is recommended to always explicitly define the SC Series
storage in /etc/multipath.conf. The following example shows multipath configurations for SC Series volumes
on RHEL 6 and newer. These configurations apply only in FC and iSCSI implementations. The SAS multipath
configuration is discussed in section 3.6.5 and should be used instead in SAS implementations.
defaults {
user_friendly_names yes
find_multipaths yes
}
devices {
device {
vendor "COMPELNT"
product "Compellent Vol"
path_grouping_policy multibus
path_selector "service-time 0" # See note below
path_checker tur
features "0"
hardware_handler "0"
prio const
failback immediate
rr_weight uniform
no_path_retry queue
}
}
multipaths {