Currently Being ModeratedDec 14, 2013 9:07 PM (in response to inajeep)
If you are using any Western Digital software such as "SmartWare" or "Drive Utility" or similarly categorized utilities, uninstall it. Such utilities are not required, and have been known to corrupt hard disk drive data or cause other trouble.
Having said that Western Digital hard disk drives have been causing trouble for many users after upgrading to Mavericks. I have not personally experienced that with any WD drives but it appears to be a popular complaint on this site.
This thread began immediately upon Mavericks' public release and continues to this day: Mavericks corrupts external hard drive
Looks like I need to find a 2nd medium for backups.
I certainly advocate having more than one backup, preferably using different backup methods, and preferably devices from different manufacturers, to preclude corruption or loss resulting from any single factor.MacBooks iMacs iPads AirPorts, OS X Mavericks (10.9), 28 years Apple!