Trond Myklebust wrote:
On Thu, 2009-03-12 at 17:00 -0400, Jim Callahan wrote:
While I'm on the subject, has there been any discussion about adding an
NFS request that would allow copying files from one location to another
on the same NFS server without requiring a round trip to a client? Its
not at all uncommon to need to move data around in this manner and it
seems a huge waste of bandwidth to have to send all this data from the
server to the client just to have the client send the data back
unaltered to a different location. Such a COPY request would be high
level along the lines of RENAME and each server vendor could optimize
this for their particular hardware architecture. For our particular
application, having such a request would make a huge difference in
performance.
I don't think anyone has talked about a server-to-server protocol, but I
believe there will be a proposal for file copy at the coming IETF
meeting. If you want server-to-server, then now is the time to speak up
and make the case. You'd probably want to start a thread on
nfsv4@xxxxxxxxxxx
Thanks for the responses Trond. I wasn't actually suggesting a
server-to-server protocol, but rather an additional client-server
protocol request to tell the server to copy files internally. The idea
being that the typical usage of "cp" via NFS is wasting bandwidth
transmitting the contents of the source file from the server to client
only to have the client send it back unaltered. If this was instead
performed internally on the server itself, it seems to me that it might
be dramatically faster and not waste valuable network bandwidth. The
calling convention would be identical to the current RENAME request.
The implementation would of course be different in this new COPY request
would create a new i-node for the target and then copy all data from he
source to target file. A vendor could choose the most efficient manner
for performing this based on their hardware/software architecture.
Thanks for the pointer to nfsv4@xxxxxxxxx I'll bring this up there as
well...
In case you are wondering, we make an application which includes version
control features somewhat along the lines of CVS or SVN. In other
words, there is a central repository for checked-in versions and
independent scratch areas for users who can have their own copies of
files. So both check-in and check-out operations frequently involve
performing a "cp" from file A to B located on the same NFS server.
--
Jim Callahan - President - Temerity Software <www.temerity.us>
--
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
