Oracle database files is locked by NFS

[hzhgz2006]

Oracle is installed in the redhat 5.4 system, the oracle database file is located in NFS storage, one day Linux system was poweroff suddenly, when linux system was powered on again, oracle could not mount database file, it promoted "file is using".
I think maybe NFS had locked the database file, but I don't know how to unlock the file.so i had to copy files to another location and mount again. but i found when I use "cp" copy files, the oracle could mount database files, but when I used "mv" to move files to new location, the oracle also could not mount. so I have two questions:
1.How to unlock NFS files?
2.I think the diffrence between "cp" and "mv" is what file properties is changed, if like that ,how can i unlock files by changing file properties?

[Rubberman]

I'm not sure how to fix this; however, placing Oracle database files on an NFS share is NOT recommended. You want the database files to be directly accessible by the server (mounted locally), and all access to the database to be via Oracle functions and API's. The server system itself should be responsible to backing up the database, to an NFS share if required, but not the other way around.