gaurav <gaurav1207@xxxxxxxxx> wrote: > i wanted to know that in linux 2.6 kernel is the data copying still > there.. in detail whenever any file is accessed from the disk by any > application program via kernel the file is copied into the kernel cache.. i > wanted to know that whether another copy of that data is copied in the user > space also or not??? I'm not sure what you're asking exactly, but CacheFiles still copies data between pages belonging to, say, NFS and pages belonging to, say, Ext3 when the data is read from the server (cold cache), and then copies them back again when there's a warm cache available. I'd like to use direct I/O, but the current direct I/O internal interface really isn't set up to do this: it assumes a userspace address to copy to/from. David