Western Digital has released an update for their WD software, that prevents the possibility of data loss after upgrading to Mavericks.

If you own a Western Digital drive, and have installed the WD software (WD Drive Manager, WD RAID Manager, or WD SmartWare), this software should be updated or removed prior to upgrading to Mavericks. See my 11.14.2014 blog postings for historical information.  http://wdc.com/wdproducts/wdsmartwareupdate/wdsmartware.asp?id=wdfGeneric&os=mac