Oracle Linux 8 - multipath -ll does not show the FS

Question

I am trying to configure a multipath for Oracle Linux 8. I am following the instructions here: https://docs.oracle.com/en/operating-systems/oracle-linux/8/stordev/multipathing.html#about-device-multipath

But even if i define my volume in the /etc/multipath.conf file, the FS does not show up in "multipath -ll"

        multipath {
                wwid                    60050763808102DF4400000000000106
                alias                   ASM_RAC1
        }
}

Bellow i will add the .conf file:

# This is a basic configuration file with some examples, for device mapper
# multipath.
#
# For a complete list of the default configuration values, run either
# multipath -t
# or
# multipathd show config
#
# For a list of configuration options with descriptions, see the multipath.conf
# man page

## By default, devices with vendor = "IBM" and product = "S/390.*" are
## blacklisted. To enable mulitpathing on these devies, uncomment the
## following lines.
blacklist_exceptions {
        device {
                vendor  "IBM"
                product "2145"
        }
}

## Use user friendly names, instead of using WWIDs as names.
#defaults {
#       user_friendly_names yes
#       find_multipaths yes
#}
##
## Here is an example of how to configure some standard options.
##
#
#defaults {
#       polling_interval        10
#       path_selector           "round-robin 0"
#       path_grouping_policy    multibus
#       uid_attribute           ID_SERIAL
#       prio                    alua
#       path_checker            readsector0
#       rr_min_io               100
#       max_fds                 8192
#       rr_weight               priorities
#       failback                immediate
#       no_path_retry           fail
#       user_friendly_names     yes
#}
defaults {
        path_selector           "round-robin 0"
        prio                    alua
        user_friendly_names     yes
        failback                immediate
        no_path_retry           fail
}

##
## The wwid line in the following blacklist section is shown as an example
## of how to blacklist devices by wwid.  The 2 devnode lines are the
## compiled in default blacklist. If you want to blacklist entire types
## of devices, such as all scsi devices, you should use a devnode line.
## However, if you want to blacklist specific devices, you should use
## a wwid line.  Since there is no guarantee that a specific device will
## not change names on reboot (from /dev/sda to /dev/sdb for example)
## devnode lines are not recommended for blacklisting specific devices.
##
#blacklist {
#       wwid 26353900f02796769
#       devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
#       devnode "^hd[a-z]"
#}
multipaths {
#
#       multipath {
#               wwid                    6005076300810B556800000000000056 
#               alias                   yellow
#               path_grouping_policy    multibus
#               path_selector           "round-robin 0"
#               failback                manual
#               rr_weight               priorities
#               no_path_retry           5


        multipath {
                wwid                    60050763808102DF4400000000000106
                alias                   ASM_RAC1
        }
}

#devices {
#       device {
#               vendor                  "COMPAQ  "
#               product                 "HSV110 (C)COMPAQ"
#               path_grouping_policy    multibus
#               path_checker            readsector0
#               path_selector           "round-robin 0"
#               hardware_handler        "0"
#               failback                15
#               rr_weight               priorities
#               no_path_retry           queue
#       }
#       device {
#               vendor                  "COMPAQ  "
#               product                 "MSA1000         "
#               path_grouping_policy    multibus
#       }
#}

devices {
        device {
                vendor "IBM"
                product "2145"
                path_grouping_policy group_by_prio
                features "1 no_path_retry queue"
                prio alua
                path_checker tur
                failback immediate
                no_path_retry "5"
                rr_min_io 1
#               find_multipaths 1
#               polling_interval 30
                dev_loss_tmo 120
        }
}


blacklist {
}

Can you please advice ?

Answer 1

multipath.conf refers to disk already discovered by OS - not vice versa.

• Check if disk is zoned to you server on SAN level
• re-scan SCSI "bus" by executing rescan-scsi-bus.sh script.
• check whether disk visible by OS by executing lsscsi
• then check WWN of a disk by executing multipath -ll
• then modify multipath.conf

PS: Linux usually prepends digit "3" to all WWNs. So your stanza from multipath.conf seems to be wrong.