Why there are "Invalid disk layout" error messages in glusterfs logs in Red Hat Gluster Storage 3.1 ?

Issue

• Why there are "Invalid disk layout" error messages in glusterfs logs in Red Hat Gluster Storage 3.1 ?

~snippet from glusterfs logs,

[dht-layout.c:767:dht_layout_dir_mismatch] 0-vXXX-dht: Invalid disk layout: invalid count 0,path = /rhs/brick/test1/0/11-2015/20151107054508_4579373860407, gfid = c78fd0e5-63ec-486f-8990-2be9754daff3
[2015-11-28 09:15:24.380525] I [MSGID: 109018] [dht-common.c:714:dht_revalidate_cbk] 0-vXXX-dht: Mismatching layouts for /rhs/brick/test1/0/11-2015/20151107054508_4579373860407, gfid = 00000000-0000-0000-0000-000000000000
[2015-11-28 09:15:24.381559] E [MSGID: 109014] [dht-layout.c:303:dht_disk_layout_merge] 0-vXXX-dht: Invalid disk layout: Invalid count 0
[2015-11-28 09:15:24.381561] W [MSGID: 109017] [dht-layout.c:388:dht_layout_merge] 0-vXXX-dht: layout merge from subvolume vCDN-replicate-2 failed
[2015-11-28 09:15:24.381783] E [MSGID: 109014] [dht-layout.c:303:dht_disk_layout_merge] 0-vXXX-dht: Invalid disk layout: Invalid count 0
[2015-11-28 09:15:24.381810] W [MSGID: 109017] [dht-layout.c:388:dht_layout_merge] 0-vXXX-dht: layout merge from subvolume vCDN-replicate-5 failed