Thanks for the great responses Brian and Quinn. I returned 32MB in the f_iosize field of the statfs structure and saw an immediate improvement. The Finder started using 512k chunks to copy data between our volume and HFS, which improved the transfer speed immensely. I also tried setting the MNT_LOCAL flag in the f_flags field of the statfs structure, but the chunk size didn't increase above 512k. I doubt HFS imposes this limit, so I'm guessing the local file system message isn't getting through. Finally, I tried copying between two of our volumes. The 100MB QT movie I copied transferred so fast that the progress window barely had a chance to draw. My tracing showed that it used 32MB chunks - what an improvement over 12k! And to answer your question Brian, no, not XFS but CXFS, SGI's clustered file system: <http://www.sgi.com/products/storage/tech/file_systems.html> Soon Mac users everywhere will be able to enjoy the chewy goodness of simultaneous direct fibre channel access to a central data store. :-) Sam _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.