Step 5. Setup DM-Multipath to list the Disks

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Device-Mapper-Multipath (or multipathd) will ignore any virtual disks with the VMware vendor string, to force the operating system to consider the relevant disks for multipathing the following steps need to be followed:

Use "lsblk" to identify the device names of the volumes which have been added.

lsblk

2. For each device to be used in the SAP HANA installation run:


udevadm info --query=all --name=/dev/<device> | grep ID_SERIAL

3. Record the value for “ID_SERIAL” and then create the multipath.conf file, ensuring that each device to be used has the value entered as a “wwid” in the multipaths field. Edit /etc/multipath.conf with the following entries:


defaults {
    user_friendly_names no
}
blacklist {
}
multipaths {
  multipath {
    wwid  36000c29dbe4185a0bbdedc9b922747c4
  }
  multipath {
    wwid  36000c2911f4ad967aa58336edcca4445
  }
  multipath {
    wwid  36000c296e9e0bfd3231ec5a7210f7a84
  }
  multipath {
    wwid  36000c29d6460812668557f320071f09d
  }
  multipath {
    wwid  36000c2983398315d62c06fa480b3fa36
  }
  multipath {
    wwid  36000c29bc7582f9acdabaa7e0e6141cd
  }
}

4. Start and enable the multipath daemon:


 systemctl enable multipathd && systemctl start multipathd 

The devices will show in the multipaths listing:


multipath -ll

5. Copy the multipath.conf file to each virtual machine to be used as in the SAP HANA scale-out installation, start and enable the multipath daemon.