Follow official UPI installation doc[1] to create UPI cluster with disk partition (create a new disk and attach to vm, then mount to /var partition)

Installation failed at bootstrap stage, and master nodes could not be ssh'd access to debug.

Manifest file for /var partition:
% cat 98-var-partition-master.yaml 
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 98-var-partition-newdisk-master
spec:
  config:
    ignition:
      version: 3.2.0
    storage:
      disks:
      - device: /dev/disk/azure/scsi1/lun0
        wipeTable: true
        partitions:
        - sizeMiB: 0
          startMiB: 0
          label: data01
          number: 1
          wipePartitionEntry: true
          shouldExist: true
      filesystems:
        - path: /var
          device: /dev/disk/by-partlabel/data01
          format: xfs
          wipeFilesystem: true
    systemd:
      units:
        - name: var.mount
          enabled: true
          contents: |
            [Unit]
            Before=local-fs.target
            [Mount]
            Where=/var
            What=/dev/disk/by-partlabel/data01
            Options=defaults,pquota
            [Install]
            WantedBy=local-fs.target


[1] https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html-single/installing_on_azure/index#installation-disk-partitioning-upi-templates_installing-restricted-networks-azure-user-provisioned

    4.18.0-rc.6 and later versions, 4.19 nightly build

    Always

    1. Follow UPI installation doc to create UPI cluster with additional a separate /var partition
    2.
    3.
    

    Installation failed

    Installation succeeded    

Issue might be related with https://github.com/openshift/installer/pull/9310

Installation with same configuration against 4.18.0-rc.5 succeeded, rc.5 does not include PR https://github.com/openshift/installer/pull/9310