If you are using Western Digital's Cloud EX2 with the globalSAN iSCSI Initiator, you may have encountered the following messages when formatting or erasing a volume:
Disk Erase failed
Disk erase failed with this error:
POSIX reports: The operation couldn't be completed.
Resource Busy.
If you also attempt to change the partition map, you may also encounter this error:
Partition failed
Partition failed with the error
File System formatter failed.
To work around this issue, you will have to temporarily change Error detection to 'none' for the affected LUN and change it back to 'Header and Data' when the format completes.