[root@an-node01 ~]# gfs2_edit -p sb /dev/drbd
drbd/         drbd0         drbd1         drbd2         drbd_an1_vg0/ drbd_an2_vg0/ drbd_sh1_vg0/
[root@an-node01 ~]# gfs2_edit -p sb /dev/drbd_sh1_vg0/xen_shared
Block #16    (0x10) of 2443264 (0x254800) (superblock)

Superblock:
  mh_magic              0x01161970(hex)
  mh_type               1                   0x1
  mh_format             100                 0x64
  sb_fs_format          1801                0x709
  sb_multihost_format   1900                0x76c
  sb_bsize              4096                0x1000
  sb_bsize_shift        12                  0xc
  master dir:           2                   0x2
        addr:           22                  0x16
  root dir  :           1                   0x1
        addr:           21                  0x15
  sb_lockproto          lock_dlm
  sb_locktable          an-cluster:xen_shared
  sb_uuid               C85EB2C5-C6C2-D8E6-EDF5-67A5D4581CEE

The superblock has 2 directories
     1. (1). 21 (0x15): Dir     root
     2. (2). 22 (0x16): Dir     master
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