get-it !!!
put in host-b
[root@esx-b:~] esxcfg-volume -l
Scanning for VMFS-3/VMFS-5 host activity (512 bytes/HB, 2048 HBs).
VMFS UUID/label: 5d9c1bad-3bd9effc-94fe-20677ce7f5a0/USB-Datastore
Can mount: Yes
Can resignature: Yes
Extent name: naa.5000000000000001:1 range: 0 - 476671 (MB)
[root@esx-b:~] esxcfg-volume -M "5d9c1bad-3bd9effc-94fe-20677ce7f5a0"
Persistently mounting volume 5d9c1bad-3bd9effc-94fe-20677ce7f5a0