Hi- Questions about NFSD should go to Bruce Fields (copied), the Linux NFS server maintainer. On Nov 29, 2013, at 6:21 AM, Charles 'Boyo <charlesboyo@xxxxxxxxx> wrote: > Hello all. > > Please guide me into to find out the impact a busy nfsd is having on > the Linux page cache. Is it possible to determine which files have > portions in the page cache? That is not possible even for local files, AFAIK. (/me prepares to eat his words). > Secondly, files opened by nfs clients do not show up in lsof (or ftop) > on the nfs server? Is there any way to list these open files and more > importantly, observe the i/o to them? NFSv3 does not have an OPEN operation. It would be difficult to tell, accurately, what an NFSv3 client was up to by looking for open files on an NFS server. NFSv4 does perform file OPENs on the wire, but our I/O metrics are per-NFS operation, not per-file. So you can see how many READs and WRITEs are done in aggregate, but not by which client, and not for a particular file. NFSv4 also has delegation, which allows clients to operate on files without contacting the NFS server. I/O activity that is cached by a client would not be visible to the storage server in any way. -- Chuck Lever chuck[dot]lever[at]oracle[dot]com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
