On Wed, 2007-07-04 at 17:09 +1000, derek kit hoong foo wrote:

Hi there,

I was wondering if someone can assist with clarifying why O_EXCL does not always work with NFS. Is it related to NFS protocol version support or export permissions mode out of the Celerra/Netapp ( e.g: mixed mode, unix file permissions ? )

As far as I know, it requires NFSv3 and your NFS client must support it also. From Linux NFS FAQ:

"It's worth noting that until early 2.6 kernels, O_EXCL creates were not atomic on Linux NFS clients."